Selected Publications (English)

Sasaki N, Kunisawa S, Ikai H, Imanaka Y. Differences between determinants of in-hospital mortality and hospitalization costs in patients with acute heart failure: a nationwide observational study from Japan. BMJ Open 2017 (in press)
Hara K, Otsubo T, Kunisawa S, Imanaka Y. Examining sufficiency and equity in the geographic distribution of physicians in Japan: a longitudinal study. BMJ Open 2016 (in press)
Nori N, Kashima H, Yamashita K, Kunisawa S, Imanaka Y. Learning Implicit Tasks for Patient-Specific Risk Modeling in ICU. Proceedings of the 31st AAAI Conference on Artificial Intelligence (AAAI), (accepted)
Kunisawa S, Fushimi K, Imanaka Y. Reducing length of hospital stay does not increase readmission rates in early-stage gastric, colon, and lung cancer surgical cases in Japanese acute care hospitals. Plos One 2016 (in press)
Hanaki N, Yamashita K, Kunisawa S, Imanaka Y. The effect of the number of request calls on the time from call to hospital arrival: a cross-sectional study of an ambulance record database in Nara prefecture, Japan. BMJ Open 2016 (in press)
Mizuno S, Kunisawa S, Sasaki N, Fushimi K, Imanaka Y. In-hospital mortality and treatment patterns in acute myocardial infarction patients admitted during national cardiology meeting dates. International Journal of Cardiology 2016 220:929・36 ; DOI: 10.1016/j.ijcard.2016.06.168
Sugiura S, Ito T, Koyama N, Sasaki N, Ikai H, Imanaka Y. Asymptomatic C-reactive protein elevation in neutropenic children. Pediatrics International 2016 0,1 ; PMID: 27362735 ; DOI: 10.1111/ped.13077
Uematsu H, Yamashita K, Kunisawa S, Fushimi K, Imanaka Y. The economic burden of Methicillin-resistant Staphylococcus aureus in community-onset pneumonia inpatients. American Journal of Infection Control 2016 Dec 1;44(12):1628-1633 ; PMID: 27475333 ; DOI: 10.1016/j.ajic.2016.05.008
Hayashida K, Umegaki T, Ikai H, Murakami G, Nishimura M, Imanaka Y. The relationship between sedative drug utilization and outcomes in critically ill patients undergoing mechanical ventilation. Journal of Anesthesia 2016 Oct;30(5):763-9 ; PMID: 27312979 ; DOI: 10.1007/s00540-016-2196-z
Uematsu H, Kunisawa S, Yamashita K, Fushimi K, Imanaka Y. Impact of weekend admission on in-hospital mortality in severe community-acquired pneumonia patients in Japan. Respirology 2016 905–910, July 2016 ; PMID: 27040008 ; DOI: 10.1111/resp.12788
Lin H, Otsubo T, Sasaki N, Imanaka Y. The determinants of long-term care expenditure and their interactions. International Journal of Healthcare Management 2016 ;9(4): 269-279 ; DOI: 10.1080/20479700.2016.1141469
Yamada G, Imanaka Y. Input-output analysis on the economic impact of medical care in Japan. Environmental Health and Preventive Medicine 2015 20(5):379-87 ; DOI: 10.1007/s12199-015-0478-y
Uematsu H, Kunisawa S, Kazuto Y, Imanaka Y. The Impact of Patient Profiles and Procedures on Hospitalization Costs through Length of Stay in Community-Acquired Pneumonia Patients Based on a Japanese Administrative Database PLOS ONE 2015 10(4): e0125284 ; DOI: 10.1371/journal.pone.0125284
  • 入院医療費に関連する要因を構造方程式モデリングを用い、入院日数を中間変数とする形で調査した。複数の患者要因が医療費に間接的に(入院日数を介して)強く関連していることが示された。
  • Possible factors associated with hospitalization costs were investigated using structural equation modeling with length of stay as an intermediate variable. The result indicated that patient profiles were generally shown to have greater indirect effects (through length of stay) on hospitalization costs than direct effects.
Lin H, Otsubo T,Imanaka Y. The effects of dementia and long-term care services on the deterioration of care-needs levels of the elderly in Japan. Medicine 2015 94(7):e525 ; PMID: 25700313 ; DOI: 10.1097/MD.0000000000000525
  • 京都府介護保険データベースと医療データベースを連結し、要介護度悪化のリスク要因を探索した。2010年から2011年の65歳以上の介護サービス利用者を解析し、「施設サービスの利用」、「男性」、「高齢」および「認知症罹患」が要介護度悪化と関連が見られた。
  • We analyzed 50,268 insurance beneficiaries aged 65 years and older who had utilized LTC services between 2010 and 2011 in Kyoto prefecture, Japan to identify predictors of care needs level deterioration and found that dementia, facility care services, the male sex, older age, and lower baseline care needs levels were associated with care needs level deterioration.
Nori N, Kashima H, Yamashita K, Ikai H, Imanaka Y. Simultaneous modeling of multiple diseases for mortality prediction in acute hospital care. Proceedings of the 21st ACM SIGKDD Conference on Knowledge Discovery and Data Mining 2015 ; DOI: 10.1145/2783258.2783308
Ukawa N, Tanaka M, Morishima T, Imanaka Y. Organizational culture affecting quality of care: guideline adherence in perioperative antibiotic use. International Journal for Quality in Health Care 2015 Feb;27(1):37-45 ; PMID: 25502553 ; DOI: 10.1093/intqhc/mzu091
  • 周術期の抗菌薬使用法において、組織文化の良好な病院ではそうでない病院に比べて、国内やCDCのガイドラインをより遵守していることが、大規模多施設組織文化調査とDPCデータから示された。
  • We demonstrated that hospitals with a high score in organizational culture were more likely to adhere to the Japanese and CDC guidelines when compared with lower scoring hospitals, using quantitative data from a multicenter culture survey and our administrative database.
Otsubo T, Goto E, Morishima T, Ikai H, Yokota C, Minematsu K, Imanaka Y. Regional variations in in-hospital mortality, care processes, and spending in acute ischemic stroke patients in Japan. Journal of Stroke and Cerebrovascular Diseases 2015 Jan;24(1):239-51 ; PMID: 25444024 ; DOI: 10.1016/j.jstrokecerebrovasdis.2014.09.016
  • NDBを用いて急性期脳梗塞治療に関する二次医療圏間の地域差を明らかにした。 院内死亡率で3.2倍、tPA使用率で5.9倍の差がみられ、急性期脳梗塞治療の地域差が顕著に存在することが明らかとなった。 また、脳梗塞治療に従事する医師数が多い地域では、院内死亡率が低く、入院医療費が高かった。 加えて、医療連携が活発である地域ほど、入院医療費が低くなる傾向がみられた。
  • Using administrative claims data from National Claims Database (NDB), this study investigates the regional variations and associations among outcomes, care processes, spending, and physician workforce availability in acute ischemic stroke care. The regional variations among SMAs in in-hospital mortality, spending, and tPA utilization were 3.2-, 1.7-, and 5.9-fold, respectively. Higher physician supply was significantly associated with lower in-hospital mortality and higher spending. Additionally, spending had a significantly negative correlation with regional continuity of care planning rate.
Uematsu H, Kunisawa S, Sasaki N, Ikai H, Imanaka Y. Development of a risk-adjusted in-hospital mortality prediction model for community-acquired pneumonia: a retrospective analysis using a Japanese administrative database. BMC Pulmonary Medicine 2014 14:203 ; PMID: 25514976 ; DOI: 10.1186/1471-2466-14-203
  • DPCデータのみで、市中肺炎の重症度予測を行った。我々の作成したモデルの識別能はAUC0.89と過去のモデルと比較し、良好であった。これらのモデルを利用すれば、病院間での正確なアウトカム比較を通じて、医療の質の改善につながる可能性がある。
  • We developed risk-adjusted mortality prediction models using only DPC administrative data. Our models showed high levels of discrimination for mortality prediction, with a c-statistic of 0.89 (95% confidence interval: 0.89-0.90). These models may support improvements in quality of care through inter-hospital comparisons.
Kobayashi D, Otsubo T, Imanaka Y. The effect of centralization of health care services on travel time and its equality. Health Policy 2014 Mar;119(3):298-306 ; PMID: 25480458 ; DOI: 10.1016/j.healthpol.2014.11.008
  • 全国健康保険協会京都支部の診療報酬請求データを用いて、虚血性心疾患患者および乳がん患者の、居住地から医療機関までのアクセス時間の地域差を明らかにした。さらに、拠点病院への集中化シミュレーションを行ったところ、平均アクセス時間は短くなり、不平等性も損なわれないことが示された。
  • Using medical reimbursement claims data from the Kyoto branch of the Japan Health Insurance Association, we found that there are the regional variations in travel time between patient residences and medical facilities for the treatment of ischemic heart disease and breast cancer. Besides, a simulation analysis of centralization to regional core hospitals demonstrated that average patient travel times could be reduced with no detrimental effects on equality of access to care.
Sasaki N, Kunisawa S, Otsubo T, Ikai H, Fushimi K, Yasumura Y, Kimura T, Imanaka Y. The relationship between the number of cardiologists and clinical practice patterns in acute heart failure ― A cross-sectional observational study. BMJ Open 2014 Dec 30;4(12):e005988 ; PMID: 25550294 ; DOI: 10.1136/bmjopen-2014-005988
  • 全国546 急性期病院における急性心不全38,668 症例を解析対象とした。本研究では、より望ましいとされる各種診療プロセス実施と病院あたり循環器専門医数の多さに関連があることが示された。また、リスク調整院内死亡率と専門医数とが負の関係を認めたことともあわせ、急性心不全の診療の質と人的資源に関連があることが示唆された。
  • We found that greater use of recommended therapeutic processes of care in acute heart failure, measured by sex-age-adjusted odds ratios, was associated with a higher number of cardiologists, using a large administrative database. Even after adjusting for disease severity factors, patients admitted to hospitals with fewer cardiologists had a higher likelihood of in-hospital mortality.
Fukuda H, Okuma K, Imanaka Y. Can experience improve hospital management? PLOS ONE 2014 Sep 24;9(9):e106884 ; PMID: 25250813 ; DOI: 10.1371/journal.pone.0106884
Ukawa N, Ikai H, Imanaka Y. Trends in hospital performance in acute myocardial infarction care: a retrospective longitudinal study in Japan. International Journal for Quality in Health Care 2014 Oct;26(5):516-523 ; PMID: 25107593 ; DOI: 10.1093/intqhc/mzu073
Goto E, Lee J, Sasaki N, Imanaka Y. Factors affecting regional variations in hospitalization expenditures of elderly residents in Japan. Journal of Public Health 2014 Volume 22, Issue 4, pp 361-370 ; DOI: 10.1007/s10389-014-0621-z
  • 高齢者一人あたり入院医療費に関連する要因やその強さは、地域の都市化度によって異なった。病床数以外に、低都市化地域では病院へのアクセスの悪さと高齢者のみ世帯割合の多さが、一方、高都市化地域では医療資源の多さが、入院医療費の高さと関連していると考えられる。全国一律の施策は、一律な効果を実現しないばかりか、地域によっては受療機会を減らすことになりかねない。医療費政策は、地域の特徴を考慮して講じるべきである。
  • Our findings emphasize the importance of taking the level of urbanization into account when analyzing regional variations in hospitalization expenditures. Policies designed to contain healthcare expenditures should take into account these regional characteristics in order to better implement regionspecific improvements that ensure affordable healthcare in arapidly aging society.
Kunisawa S, Yamashita K, Ikai H, Otsubo T, Imanaka Y. Survival analyses of postoperative lung cancer patients: an investigation using Japanese administrative data. SpringerPlus 2014 (in press) ; PMID: 24826376 ; DOI: 10.1186/2193-1801-3-217
  • Stage情報を有するDPCデータを用いて、肺癌術後5年間の生存解析を行った。臨床登録データと類似の結果を呈し、また、症例の多い病院群で高い生存率がみられた。今後、広域地域のがんの治療成績のモニタリングなどに利用しうる、Administrative Databaseの潜在力を示した。我が国のAdministrative Databaseを用いれば、限界はあるものの、低コストで、迅速に、しかもデータ整備が不十分な病院群データも対象として生存率を推計できる等の利点がある。
  • Using an administrative database with staging information, we analyzed5-year-survival curves after the initial hospitalization due to primarynon-small cell lung cancer. The curves approximated those of the cancerregistry database. Hospitals with higher case volume showed higher 5-yearsurvival. We showed a potential of the Japanese administrative database totimely describe and monitor cancer survival rates, low in cost, of all thehospitals including those weak in data management.
Kobuse H, Morishima T, Tanaka M, Murakami G, Hirose M, Imanaka Y. Visualizing variations in organizational safety culture across an inter-hospital multifaceted workforce. Journal of Evaluation in Clinical Practice 2014 2014;20(3):273-80. ; PMID: 24661540 ; DOI: 10.1111/jep.12123
Kunisawa S, Kobayashi D, Lee J, Otsubo T, Ikai H, Yokota C, Minematsu K, Imanaka Y. Factors associated with the administration of tissue plasminogen activator for acute ischemic stroke. Journal of Stroke and Cerebrovascular Diseases 2014 23(4):724-731. ; PMID: 23910512 ; DOI: 10.1016/j.jstrokecerebrovasdis.2013.06.033
  • 急性期脳梗塞患者の約5%にtPA投与が見られた。tPA投与には年齢や重症度が関連するが、患者宅と病院との距離には関連が見られなかった。リスク調整を行ったうえで、救急搬送が行われている場合にはtPA投与に至る割合が約4倍となり(オッズ比 4.3)、救急搬送の重要性が再認識された。
  • Intravenous tPA was found to be administered to approximately 5% of acute ischemic stroke patients. The administration of tPA was associated with age and stroke severities, but not with distance from patient home to hospital. After risk adjustment, ambulance use was significantly associated with tPA use (OR: 4.3), which emphasizes the need for emergency calls for an ambulance in suspected stroke patients.
Morishima T, Lee J, Otsubo T, Imanaka Y. Association of health care expenditures with aggressive versus palliative care for cancer patients at the end of life: A cross-sectional study using claims data in Japan. International Journal for Quality in Health Care 2014 26(1):79-86. ; PMID: 24225269 ; DOI: 10.1093/intqhc/mzt081
  • 終末期がん患者への過剰医療や緩和ケアを示す指標のうちのいくつかが終末期医療費の増加と関連していることがレセプトデータから明らかになった。終末期がん患者への過剰治療を適正化すれば終末期医療費を削減できるかもしれないことが示唆された。
  • We revealed that indicators of both aggressive and palliative end-of-life care for terminally-ill cancer patients were associated with higher healthcare spending at the end of life, using health insurance claims data. These results may support the coherent development of measures to optimize aggressive care and reduce the financial burdens of terminal cancer care.
Sasaki H, Otsubo T, Imanaka Y. Widening disparity in the geographic distribution of pediatricians in Japan. Human Resources for Health 2013 Nov 22;11:59 ; PMID: 24267031 ; DOI: 10.1186/1478-4491-11-59
  • 小児科医師数の推移は、地域の都会化度因子と医療資源因子で、4タイプに分類された。都会化が進むも医療資源が少ない地域で最も増加が激しかった。一方、田舎で医療資源が少ない地域では、数は維持されているが、若い医師や女性医師など新たな医師の流入は無く、すでに高齢な医師のさらなる高齢化が進んでいる。これらの地域では、近い将来に医師不足が急速に問題化する恐れが強い。
  • The trends of the pediatrician workforce were classified into four types according to the two factors: urbanization and healthcare resources. In highly urbanized and low-resource areas, the workforce increased most sharply. On the other hand, in lowly urbanized and low-resource areas, the already-old workforce were maintained in size without entry of younger or women doctors, and they were getting older. This situation alarms a dangerous state of future critical shortage in doctors in these areas.
Kunisawa S, Morishima T, Ukawa N, Ikai H, Otsubo T, Ishikawa KB, Yokota C, Minematsu K, Fushimi K, Imanaka Y. The association of geographical factors with administration of tissue plasminogen activator for acute ischemic stroke. Journal of American Heart Association 2013 Sep 17;2(5):e000336 ; PMID: 24045119 ; DOI: 10.1161/JAHA.113.000336
  • 全国に分布する603病院の急性期脳梗塞114,194例を分析した。tPA投与率は、全体の約5%で、高齢者および重症例でより低い傾向がみられ、運転アクセス時間とは関係なかった。関連因子を調整しても、救急搬送の有無に強く関連していた(オッズ比 4)。これらの結果は、都会か地方かに係らず同様であり、脳卒中が疑われるときに迅速に救急車を呼ぶことの重要性を示唆するものであった。
  • We analyzed administrative claims data from 114,194 acute ischemic stroke cases admitted to 603 hospitals in Japan. Approximately 5.1% of patients received tPA. The administration of tPA was associated with patient age and severity of stroke symptoms, but driving time showed no association. Ambulance use was significantly associated with tPA administration (OR: 4.0) even after adjustment for covariates. These results are consistent across differentially urbanized regions, and suggest the importance of calling an ambulance for suspected stroke.
Park S, Sasaki N, Morishima T, Ikai H, Imanaka Y. The number of cardiologists, case volume and in-hospital mortality in acute myocardial infarction patients. International Journal of Cardiology 2013 Oct;168(4):4470-1 ; PMID: 23871346 ; DOI: 10.1016/j.ijcard.2013.06.139
  • 多くの先行研究では急性心筋梗塞の症例数とアウトカムでの負の関係が報告されてきたが、本研究では症例数より、循環器専門医数が院内死亡率と負の関係であることがわかった。循環器専門医を集中させることがより医療の質を高める効果的な方案になりえると理解する必要がある。
  • Several studies have demonstrated an inverse volume-outcome relationship in AMI, but our study showed that in-hospital mortality was inversely associated with the number of cardiologists per hospital, but not with case volume. This founding suggests understanding the possible advantages of concentrating cardiologists to specific institutions in order to improve the quality of care for AMI patients.
Park S, Lee J, Ikai H, Otsubo T, Imanaka Y. Decentralization and centralization of healthcare resources: investigating the associations of hospital competition and number of cardiologists per hospital with mortality and resource utilization in Japan. Health Policy 2013 Nov;113(1-2):100-9. ; PMID: 23830562 ; DOI: 10.1016/j.healthpol.2013.06.005
  • 循環器専門医数の多い病院(集中化)とDPC病院数の多い二次医療圏(分散化)では、急性心筋梗塞患者における死亡率が低いことがわかった。医療の質を高めるのための集中化と分散化のメカニズムを理解して、実際に政策を立てる際にそれらのバランスを取る必要がある。
  • Centralization of cardiologist at the hospital level and decentralization of acute hospitals at the regional level may be contributing factors for improving the quality of care in Japan. Policymakers need to strike a balance between these two approaches to improve healthcare provision and quality.
Sasaki N, Lee J, Park S, Umegaki T, Kunisawa S, Otsubo T, Ikai H, Imanaka Y. Development and Validation of an Acute Heart Failure-Specific Mortality Predictive Model Based on Administrative Data. Canadian Journal of Cardiology 2013 Sep;29(9):1055-61 ; PMID: 23395282 ; DOI: 10.1016/j.cjca.2012.11.021
  • 85急性期病院における8620名の急性心不全患者について、DPCデータ内の年齢、性別の他、入院時の併存症、NYHA分類などを用いて、高い院内死亡予測力をもつモデルを開発した(C-statistic = 0.80)。当該モデルを用いて多くの病院で同様の定義でリスク調整予測死亡率を算出することができるようになり、評価や改善に使いうる。
  • We developed a new acute heart failure (AHF) mortality prediction model using an administrative database in Japan. The use of only 11 variables including older age, New York Heart Association (NYHA) functional class and severe comorbid conditions were able to accurately predict in-hospital mortality (C-statistic = 0.80). This model may facilitate risk adjustments for AHF and can contribute to further hospital evaluations.
Park S, Lee J, Ikai H, Otsubo T, Ukawa N, Imanaka Y. Quality of care and in-hospital resource use in acute myocardial infarction: Evidence from Japan. Health Policy 2013 Aug;111(3):264-72 ; PMID: 23800607 ; DOI: 10.1016/j.healthpol.2013.05.015
  • 医療政策を立てる際、より低い医療費はより高い効率性を示しているという仮定で、単純に医療費のみに着目する考え方がある。しかし、本研究では急性心筋梗塞における医療費の高い病院グループに比べ、低い病院グループでは死亡率が高いことがわかった。 政策立案者はこの関係を理解した上で、医療政策を立てる必要がある。
  • At first glance, hospitals with lower resource use may appear to possess a higher level of efficiency, and policymakers may be inclined to set standards of low healthcare spending to contain costs. However, our study showed that poor quality of care in outcome measures was associated with lower resource use among AMI patients. Policymakers need to understand this inverse association before health policymaking.
Kunisawa S, Otsubo T, Lee J, Imanaka Y. Improving the assessment of prescribing: Use of a 'substitution index'. Journal of Health Services Research & Policy 2013 Jul;18(3):138-43 ; PMID: 23595576 ; DOI: 10.1177/1355819612473593
  • 日本での後発薬の使用状況を、部門別、薬効別で解析した。後発薬の利用可能の最大値は部門や取扱い薬により大きく異なり、最大値を考慮した公正な指標を提案する。
  • We analyzed the use of generic drugs categorized by sectors and drug types. We found not only differences in generic drug use rates, but also significant differences in maximum substitutability among sectors and clinical disciplines. We propose a fairer measure to assess the use of generic drugs in a policy context.
Yamashita K, Ikai H, Nishimura M, Fushimi K, Imanaka Y. Effect of certified training facilities for intensive care specialists on mortality in Japan. Critical Care and Rresuscitation 2013 15(1):28-32. ; Journal PMID: 23432498
  • ICU専門医研修施設に認定されたICUで治療を受けた患者の予後とそうでない患者との予後とを、リスク要因を統計的に調整して比較し、前者が優れていたことを示した。
  • Patients who were treated in ICUs certified as training facilities for intensive care specialists had better outcome than patients treated in ICU without this certification.
Umegaki T, Nishimura M, Tajimi K, Fushimi K, Ikai H, Imanaka Y. An in-hospital mortality equation for mechanically ventilated patients in intensive care units. Journal of Anesthesia 2013 Aug;27(4):541-9 ; PMID: 23475475 ; DOI: 10.1007/s00540-013-1557-0
Lee J, Morishima T, Kunisawa S, Sasaki N, Otsubo T, Ikai H, Imanaka Y. Derivation and validation of in-hospital mortality prediction models in ischaemic stroke patients using administrative data. Cerebrovascular Diseases 2013 35(1):73-80. ; PMID: 23429000 ; DOI: 10.1159/000346090
  • DPCの調査項目データとして追加された脳梗塞患者の重症度情報を用い、精度の高い死亡予測モデルを開発した。
  • Recent additions of disease severity information to Japanese administrative data (DPC data) were shown to achieve high accuracy of mortality prediction in stroke patients, thereby supporting further outcomes research.
Motohashi T, Hamada H, Lee J, Sekimoto M, Imanaka Y. Factors associated with prolonged length of hospital stay of elderly patients in acute care hospitals in Japan: a multilevel analysis of patients with femoral neck fracture. Health Policy 2013 111(1):60-7. ; PMID: 23628484 ; DOI: 10.1016/j.healthpol.2013.03.014
  • 日本の急性期病院における高齢患者の在院日数の長期化や転院に関連する、地域の医療・介護資源を調べた。その結果、二次医療圏内の医療・介護資源の充実(療養病床数等)は、患者の転院をより可能にし、在院日数を短縮させることが示唆された。
Tanaka M, Lee J, Ikai H, Imanaka Y. Development of efficiency indicators of operating room management for multi-institutional comparisons. Journal of Evaluation in Clinical Practice 2013 19(2):335-41. ; PMID: 22332870 ; DOI: 10.1111/j.1365-2753.2012.01829.x
  • 手術室あたりの手術件数、手術室利用時間、手術手技報酬は病院規模や人員数等の違いが大きな影響を及ぼす(R2=0.34~0.5)。224病院の医療管理データを用い、これらの違いを統計学的に調整し多施設比較可能な手術室運用の効率性評価指標を開発した。
Lee J, Morishima T, Park S, Otsubo T, Ikai H, Imanaka Y. The association between health care spending and quality of care for stroke patients in Japan. Journal of Health Services Research & Policy 2013 18(2): 77-82. ; DOI: 10.1177/1355819612473454
  • 脳梗塞に対する医療費が低い地域では、プロセスの質指標が低いことが示された。一方、医療費と院内死亡率に関連は見られなかった。
  • Testing the associations between spending and quality of care revealed that lower spending regions were associated with reduced performance in processes, but not with in-hospital mortality in ischemic stroke care.
Morishima T, Ikai H, Imanaka Y. Cost-effectiveness analysis of omalizumab for the treatment of severe asthma in Japan and the value of responder prediction methods based on a multinational trial. Value in Health Regional Issues 2013 2(1): 29–36. ; DOI: 10.1016/j.vhri.2013.01.007
  • 気管支喘息の高額薬剤であるオマリズマブの費用対効果を調べるとともに、レスポンダー(よく効く患者)を予測する検査方法の発見の経済的価値を見積もった。
  • We conducted an economic evaluation of omalizumab in patients with severe asthma and estimated the expected value of perfect information of responder prediction methods.
Morishima T, Lee J, Otsubo T, Ikai H, Imanaka Y. Impact of hospital case volume on quality of end-of-life care in terminal cancer patients. Journal of Palliative Medicine 2013 16(2):173-8. ; PMID: 23140184 ; DOI: 10.1089/jpm.2012.0361
  • がん患者の終末期医療の質と、病院の症例数とが相関していることを発見した。
  • We demonstrated an association between quality of end-of-life care and case volume, using a large-scale insurance claims database.
Morishima T, Imanaka Y, Otsubo T, Hayashida K, Watanabe T, Tsuji I. Burden of household environmental tobacco smoke on medical expenditure for Japanese women: a population-based cohort study. Journal of Epidemiology 2013 23(1):55-62. ; PMID: 23183111 ; DOI: 10.2188/jea.JE20120072
  • コホート研究において家庭内で受動喫煙に暴露された女性とそうでない女性の医療費とを比較し、受動喫煙に起因する超過医療費を評価した。
  • This is a long-term cohort study that assessed the excess in healthcare spending caused by environmental tobacco smoke in homes.
Morishima T, Otsubo T, Gotou E, Kobayashi D, Lee J, Imanaka Y. Physician adherence to asthma treatment guidelines in Japan: focus on inhaled corticosteroids. Journal of Evaluation in Clinical Practice 2013 19(2):223-9. ; PMID: 21689218 ; DOI: 10.1111/j.1365-2753.2011.01708.x
  • 気管支喘息治療のガイドラインで重症度に関係なく推奨されている吸入ステロイド剤の処方の有無に関係する医療者側の要因と患者側の要因を明らかにした。
  • We explored the determinants of prescription of inhaled corticosteroids for patients with asthma, using an insurance claims database.
Hamada H, Sekimoto M, Imanaka Y. Effects of the per diem prospective payment system with DRG-like grouping system (DPC/PDPS) on resource usage and healthcare quality in Japan. Health Policy 2012 107(2-3):194-201. ; PMID: 22277879 ; DOI: 10.1016/j.healthpol.2012.01.002
Kunisawa S, Ikai H, Imanaka Y. Incidence and prevention of postoperative venous thromboembolism: are they meaningful quality indicators in Japanese health care settings? World Journal of Surgery 2012 36(2):280-6. ; PMID: 21879424 ; DOI: 10.1007/s00268-011-1229-x
Ikai H, Morimoto T, Shimbo T, Imanaka Y, Koike K. Impact of postgraduate education on physician practice for community-acquired pneumonia. Journal of Evaluation in Clinical Practice 2012 18(2):389-95. ; PMID: 21208347 ; DOI: 10.1111/j.1365-2753.2010.01594.x
Umegaki T, Ikai H, Imanaka Y. The impact of acute organ dysfunction on patients' mortality with severe sepsis. Journal of Anaesthesiology, Clinical Pharmacology 2011 27(2):180-4. ; PMID: 21772676 ; DOI: 10.4103/0970-9185.81816
Fukuda H, Lee J, Imanaka Y. Costs of hospital-acquired infection and transferability of the estimates: a systematic review. Infection 2011 39(3):185-99. ; PMID: 21424853 ; DOI: 10.1007/s15010-011-0095-7
  • 院内感染によるコストの研究のシステマティックレビューを行い、原価計算の方法とその記述レベルを評価した。その結果、原価の要素と単価の明示を含む、計算過程の透明性や再現性を確保した研究は少なく、1割に満たなかった。
  • A systematic review showed that only <10% of studies that produced cost estimates of HAIs had a high level of transferability, with reported cost components and unit costs.
Umegaki T, Sekimoto M, Imanaka Y. Impact of intensive care unit physician on care processes of patients with severe sepsis in teaching hospitals. Journal of Anesthesia & Clinical Research. 2011 2(2):120-125. ; DOI: 10.4172/2155-6148.1000120
Lee J, Imanaka Y, Sekimoto M, Nishikawa H, Ikai H, Motohashi T; Quality Indicator/Improvement Project (QIP) Expert Group for Clinical Evaluation. Validation of a novel method to identify healthcare-associated infections. Journal of Hospital Infection 2011 77(4):316-20. ; PMID: 21277647 ; DOI: 10.1016/j.jhin.2010.11.013
  • DPCデータから院内感染の発生を同定する方法を開発した。チャートレビュー結果と照合し、その方法の妥当性を実証した。
  • Chart review analysis was used to demonstrate the high validity of an HAI identification method based on antibiotic utilization patterns in administrative data.
Otsubo T, Imanaka Y, Lee J, Hayashida K. Evaluation of resource allocation and supply-demand balance in clinical practice with high-cost technologies. Journal of Evaluation in Clinical Practice 2011 17(6):1114-21. ; PMID: 20630009 ; DOI: 10.1111/j.1365-2753.2010.01484.x
  • 我が国では、高額医療機器設置の導入規制がないが、世界的に見て設置数は非常に多い。そこで地域の需給バランスを評価する指標を開発し、MRIとESWLに適用し、過剰供給地域群とその特性を見出した。
Fukuda H, Lee J, Imanaka Y. Variations in analytical methodology for estimating costs of hospital-acquired infections: a systematic review. Journal of Hospital Infection 2011 77(2):93-105. ; PMID: 21145131 ; DOI: 10.1016/j.jhin.2010.10.006
  • 院内感染に関わるコストの推定方法について系統的レビューを行い、その動向を示した。
  • A systematic review tracked the distribution and trends in HAI cost estimation methodologies, which focused on matched comparisons, regression models, and case reviews.
Lee J, Imanaka Y, Sekimoto M, Ikai H, Otsubo T. Healthcare-associated infections in acute ischemic stroke patients from 36 Japanese hospitals: risk-adjusted economic and clinical outcomes. International Journal of Stroke. 2011 6(1): 16-24. ; PMID: 21205236 ; DOI: 10.1111/j.1747-4949.2010.00536.x
  • 脳梗塞患者において、多変量でリスク調整を行い、医療費、在院日数、院内死亡率の、院内感染による増分を定量的に示した。
  • We identified HAI incidence in stroke patients based on antibiotic utilization patterns. We quantified the increases in hospital charges, length of stay, and mortality due to HAI by statistically controlling effects of the other risk factors.
Nishikawa H, Imanaka Y, Sekimoto M, Ikai H. Verification bias in assessment of the utility of MRI in the diagnosis of cruciate ligament tears. American Journal of Roentgenology 2010 195(5):W357-64. ; PMID: 20966301 ; DOI: 10.2214/AJR.10.4189
Umegaki T, Sekimoto M, Ikai H, Imanaka Y. Current anticoagulation therapy for sepsis-induced disseminated intravascular coagulation in Japan: results of multicenter study using administrative data. Journal of the Japanese Society of Intensive Care Medicine 2010 17(4):555-559.
Umegaki T, Sekimoto M, Hayashida K, Imanaka Y. An outcome prediction model for adult intensive care. Critical Care and Resuscitation : journal of the Australasian Academy of Critical Care Medicine 2010 12(2):96-103. ; PMID: 20513217
Regenbogen SE, Hirose M, Imanaka Y, Oh EH, Fukuda H, Gawande AA, Takemura T, Yoshihara H. A comparative analysis of incident reporting lag times in academic medical centres in Japan and the USA. Quality and Safety in Health Care 2010 19(6):e10-e13. ; PMID: 20194219 ; DOI: 10.1136/qshc.2008.029215
Sasaki H, Imanaka Y, Sekimoto M, Lee J, Otsubo T. Antimicrobial prescription patterns for children hospitalized with pneumonia and compliance to guidelines in Japan: a multicenter study. Journal of Evaluation in Clinical Practice 2010 16(5):987-9. ; PMID: 20626540 ; DOI: 10.1111/j.1365-2753.2009.01237.x
Sekimoto M, Imanaka Y, Shirai T, Sasaki H, Komeno T, Lee J, Yoshihara K, Ashihara E, Maekawa T. Risk-adjusted assessment of incidence and quantity of blood use in acute-care hospitals in Japan: an analysis using administrative data. Vox Sanguinis 2010 98(4):538-46. ; PMID: 20002605 ; DOI: 10.1111/j.1423-0410.2009.01290.x
Murakami G, Imanaka Y, Kobuse H, Lee J, Goto E. Patient perceived priorities between technical skills and interpersonal skills: their influence on correlates of patient satisfaction. Journal of Evaluation in Clinical Practice 2010 16(3):560-8. ; PMID: 20438604 ; DOI: 10.1111/j.1365-2753.2009.01160.x
Hayashida K, Imanaka Y, Murakami G, Takahashi Y, Nagai M, Kuriyama S, Tsuji I. Difference in lifetime medical expenditures between male smokers and non-smokers. Health Policy 2010 94(1):84-9. ; PMID: 19775772 ; DOI: 10.1016/j.healthpol.2009.08.007
Fukuda H, Imanaka Y, Hirose M, Hayashida K Impact of system-level activities and reporting design on the number of incident reports for patient safety. Quality and Safety in Health Care 2010 19(2):122-7. ; PMID: 20351160 ; DOI: 10.1136/qshc.2008.027532
Lee J, Imanaka Y, Sekimoto M, Ishizaki T, Hayashida K, Ikai H, Otubo T. Risk-adjusted increases in medical resource utilization associated with health care-associated infections in gastrectomy patients. Journal of Evaluation in Clinical Practice 2010 16(1):100-6. ; PMID: 20367820 ; DOI: 10.1111/j.1365-2753.2009.01121.x
  • 胃切除患者の院内感染を、DPCデータにて抗菌薬使用のパターンから同定する手法を開発し、医療費、抗菌薬薬剤費、在院日数における、院内感染による増加分を定量的に示した。
  • In gastrectomy patients, we developed an HAI identification method based on antibiotic utilization patterns in administrative data, and analyzed HAI-associated increases in hospital costs, antibiotic costs, and length of stay.
Kuwabara K, Matsuda S, Fushimi K, Ishikawa KB, Horiguchi H, Hayashida K, Fujimori K. Contribution of bile duct drainage on resource use and clinical outcome of open or laparoscopic cholecystectomy in Japan. Journal of evaluation in clinical practice. 2010 16(1):31-8. ; PMID: 20367813
Kuwabara K, Matsuda S, Imanaka Y, Fushimi K, Hashimoto H, Ishikawa KB, Horiguchi H, Hayashida K, Fujimori K, Ikeda S, Yasunaga H. Injury severity score, resource use, and outcome for trauma patients within a Japanese administrative database. Journal of Trauma - Injury, Infection and Critical Care 2010 68(2):463-70. ; PMID: 19935111 ; DOI: 10.1097/TA.0b013e3181a60275
Kuwabara K, Matsuda S, Anan M, Fushimi K, Ishikawa KB, Horiguchi H, Hayashida K, Fujimori K. Difference in resource utilization between patients with acute and chronic heart failure from Japanese administrative database. International journal of cardiology. 2010 141(3):254-9. ; PMID: 19157584
Bech M, et al.(incl. Imanaka Y) The influence of economic incentives and regulatory factors on the adoption of treatment technologies: A case study of technologies used to treat heart attacks. Health Economics 2009 18(10):1114-1132. ; PMID: 18972326 ; DOI: 10.1002/hec.1417
Fukuda H, Imanaka Y, Ishizaki T, Okuma K,Shirai T. Change in clinical practice after publication of guidelines on breast cancer treatment. International Journal for Quality in Health Care 2009 21(5):372-8. ; PMID: 19700780 ; DOI: 10.1093/intqhc/mzp037
Nishikawa H, Imanaka Y, Sekimoto M, Hayashida K, Ikai H. Influence of verification bias on the assessment of MRI in the diagnosis of meniscal tear. American Journal of Roentgenology 2009 193(6):1596-602. ; PMID: 19933653 ; DOI: 10.2214/AJR.08.2223
Nojo T, Imanaka Y, Ishizaki T, Sekimoto M, Yoshino M, Kurosawa T, Takao H, Ohtomo K. Lung cancer incidence in middle-aged men estimated by low-dose computed tomography screening. Lung Cancer 2009 65(1):56-61. ; PMID: 19019487 ; DOI: 10.1016/j.lungcan.2008.10.004
Shirai T, Imanaka Y, Sekimoto M, Ishizaki T; QIP Ovarian Cancer Expert Group. Primary chemotherapy patterns for ovarian cancer treatment in Japan. The Journal of Obstetrics and Gynaecology Research 2009 35(5):926-34. ; PMID: 20149043 ; DOI: 10.1111/j.1447-0756.2009.01033.x
Kawasaki K, Sekimoto M, Ishizaki T, Imanaka Y. Work stress and workload of full-time anesthesiologists in acute care hospitals in Japan. Journal of Anesthesia 2009 23(2):235-41. ; PMID: 19444563 ; DOI: 10.1007/s00540-008-0736-x
Sekimoto M, Imanaka Y, Kobayashi H, Okubo T, Kizu J, Kobuse H, Mihara H, Tsuji N, Yamaguchi A; Japan Council for Quality Health Care, Expert Group on Healthcare-Associated Infection Control and Prevention. Factors affecting performance of hospital infection control in Japan. American Journal of Infection Control 2009 37(2):136-42. ; PMID: 19249641 ; DOI: 10.1016/j.ajic.2008.03.005
Hayashida K, Imanaka Y, Otsubo T, Kuwabara K, Ishikawa KB, Fushimi K, Hashimoto H, Yasunaga H, Horiguchi H, Anan M, Fujimori K, Ikeda S, Matsuda S. Development and analysis of a nationwide cost database of acute-care hospitals in Japan. Journal of Evaluation in Clinical Practice 2009 15(4):626-33. ; PMID: 19522724 ; DOI: 10.1111/j.1365-2753.2008.01063.x
Fukuda H, Imanaka Y, Hirose M, Hayashida K. Factors associated with system-level activities for patient safety and infection control. Health Policy 2009 89(1):26-36. ; PMID: 18538442 ; DOI: 10.1016/j.healthpol.2008.04.009
Fukuda H, Imanaka Y. Assessment of transparency of cost estimates in economic evaluations of patient safety programmes. Journal of Evaluation in Clinical Practice 2009 15(3):451-9. ; PMID: 19366392 ; DOI: 10.1111/j.1365-2753.2008.01033.x
Fukuda H, Imanaka Y, Kobuse H, Hayashida K, Murakami G. The subjective incremental cost of informed consent and documentation in hospital care: a multicentre questionnaire survey in Japan. Journal of Evaluation in Clinical Practice 2009 15(2):234-41. ; PMID: 19335478 ; DOI: 10.1111/j.1365-2753.2008.00987.x
Kuwabara K, Matsuda S, Fushimi K, Ishikawa KB, Horiguchi H, Fujimori K, Hayashida K. Impact of timing of cholecystectomy and bile duct interventions on quality of cholecystitis care. International Journal of Surgery 2009 7(3):243-9 ; PMID: 19376278
Kuwabara K, Matsuda S, Fushimi K, Anan M, Ishikawa KB, Horiguchi H, Hayashida K, Fujimori K. Differences in practice patterns and costs between small cell and non-small cell lung cancer patients in Japan. The Tohoku Journal of Experimental Medicine. 2009 217(1):29-35. ; PMID: 19155605
Fukuda H Imanaka Y, Hirose M, Hayashida K. Economic evaluations of maintaining patient safety systems in teaching hospitals. Health Policy 2008 88(2-3):381-91. ; PMID: 18514966 ; DOI: 10.1016/j.healthpol.2008.04.004
Kuwabara K, Imanaka Y, Matsuda S, Fushimi K, Hashimoto H, Ishikawa KB, Horiguchi H, Hayashida K, Fujimori K. Cost of open versus laparoscopic appendectomy. La Clinica Terapeutica 2008 159(3):155-63. ; PMID: 18594744
Sekimoto M, Kakutani C, Inoue I, Ishizaki T, Hayashida K, Imanaka Y. Management patterns and healthcare costs for hospitalized patients with cerebral infarction. Health Policy 2008 88(1):100-9. ; PMID: 18378349 ; DOI: 10.1016/j.healthpol.2008.01.013
Fukuda H, Imanaka Y, Hayashida K. Cost of hospital-wide activities to improve patient safety and infection control: a multi-centre study in Japan. Health Policy 2008 87(1):100-11. ; PMID: 18394745 ; DOI: 10.1016/j.healthpol.2008.02.006
Ishizaki T, Imanaka Y, Oh EH, Sekimoto M, Hayashida K, Kobuse H. Association between patient age and hospitalization resource use in a teaching hospital in Japan. Health Policy 2008 87(1):20-30. ; PMID: 18067988 ; DOI: 10.1016/j.healthpol.2007.10.007
Sekimoto M, Imanaka Y, Kobayashi H, Okubo T, Kizu J, Kobuse H, Mihara H, Tsuji N, Yamaguchi A; Japan Council for Quality Health Care, Expert Group on Healthcare-Associated Infection Control and Prevention. Impact of hospital accreditation on infection control programs in teaching hospitals in Japan. American Journal of Infection Control 2008 36(3):212-9. ; PMID: 18371518 ; DOI: 10.1016/j.ajic.2007.04.276
Kuwabara K, Matsuda S, Imanaka Y, Fushimi K, Hashimoto H, Ishikawa K. The effect of age and procedure on resource use for patients with cerebrovascular disease. Journal of Health Services Research and Policy 2008 13(1):26-32. ; PMID: 18325153 ; DOI: 10.1258/jhsrp.2007.007009
Ishizaki T, Imanaka Y, Sekimoto M, Fukuda H, Mihara Hwith the Treatment of Subarachnoid Hemorrhage Expert Group. Comparisons of risk-adjusted clinical outcomes for patients with aneurysmal subarachnoid haemorrhage across eight teaching hospitals in Japan. Journal of Evaluation in Clinical Practice 2008 14(3):416-21. ; PMID: 18373576 ; DOI: 10.1111/j.1365-2753.2007.00882.x
Kuwabara K, Imanaka Y, Matsuda S, Fushimi K, Hashimoto H, Ishikawa KB, Horiguchi H, Hayashida K, Fujimori K. The association of the number of comorbidities and complications with length of stay, hospital mortality and LOS high outlier, based on administrative data. Environmental Health and Preventive Medicine 2008 13(3):130-7. ; PMID: 19568897 ; DOI: 10.1007/s12199-007-0022-9
Kuwabara K, Imanaka Y, Matsuda S, Fushimi K, Hashimoto H, Ishikawa KB, Horiguchi H, Hayashida K, Fujimori K. Impact of age and procedure on resource use for patients with ischemic heart disease. Health Policy 2008 85(2):196-206. ; PMID: 17825454 ; DOI: 10.1016/j.healthpol.2007.07.015
Oh EH, Imanaka Y, Hayashida K, Kobuse H. Meta-analysis comparing clinical effectiveness of drug-eluting stents, bare metal stents and coronary artery bypass surgery. International Journal of Evidence-Based Healthcare 2007 5(3):296-304. ; PMID: 21631793 ; DOI: 10.1111/j.1479-6988.2007.00071.x
Fushimi K, Hashimoto H, Imanaka Y, Kuwabara K, Horiguchi H, Ishikawa KB, Matsuda S. Functional mapping of hospitals by diagnosis-dominant case-mix analysis. BMC Health Services Research 2007 7(4):50-57. ; PMID: 17425788 ; DOI: 10.1186/1472-6963-7-50
Hayashida K, Imanaka Y, Sekimoto M, Kobuse H, Fukuda H. Evaluation of acute myocardial infarction in-hospital mortality using a risk-adjustment model based on Japanese administrative data. Journal of International Medical Research 2007 35(5):590-596. ; PMID: 17900397
Hayashida K, Imanaka Y, Fukuda H. Measuring hospital-wide activity volume for patient safety and infection control: a multi-centre study in Japan. BMC Health Services Research 2007 7(9):140-146. ; PMID: 17764578 ; DOI: 10.1186/1472-6963-7-140
Hirose M, Regenbogen SE, Lipsitz S, Imanaka Y, Ishizaki T, Sekimoto M, Oh EH, Gawande AA. Lagtime in incident reporting system at a university hospital in Japan. Quality and Safety in Health Care 2007 16(2):101-4. ; PMID: 17403754 ; DOI: 10.1136/qshc.2006.019851
Evans E, Imanaka Y, Sekimoto M, Ishizaki T, Hayashida K, Fukuda H, Oh EH. Risk adjusted resource utilization for AMI patients treated in Japanese hospitals. Health Economics 2007 16(4):347-359. ; PMID: 17031780 ; DOI: 10.1002/hec.1177
Murakami G, Inoue T, Saito M. On cognitive reliability of hospital organisational environment and work performance. International Journal of Healthcare Technology and Management 2007 8(4):388-398.
Kuwabara K, Imanaka Y, Matsuda S, Fushimi K, Hashimoto H, Ishikawa KB, Horiguchi H. Profiling of resource use variation among six diseases treated at 82 Japanese special functioning hospitals, based on administrative data. Health Policy 2006 78(2-3):306-18 ; PMID: 16343686 ; DOI: 10.1016/j.healthpol.2005.11.006
Sekimoto M, Imanaka Y, Kitano N, Ishizaki T, Takahashi O. Why are physicians not persuaded by scientific evidence? A grounded theory interview study. BMC Health Services Research 2006 6(7):92-100. ; PMID: 16872522 ; DOI: 10.1186/1472-6963-6-92
Sekimoto M, Imanaka Y, Hirose M, Ishizaki T, Murakami G, Fukata Y; QIP Cholecystectomy Expert Group. Impact of treatment policies on patient outcomes and resource utilization in acute cholecystitis in Japanese hospitals. BMC Health Services Research 2006 6(3):40-46. ; PMID: 16569249 ; DOI: 10.1186/1472-6963-6-40
Ishizaki T, Yoshida H, Suzuki T, Watanabe S, Niino N, Ihara K, Kim H, Fujiwara Y, Shinkai S, Imanaka Y. Effects of cognitive function on functional decline among community-dwelling non-disabled older Japanese. Archives of Gerontology and Geriatrics 2006 42(1):47-58. ; PMID: 16081171 ; DOI: 10.1016/j.archger.2005.06.001
Kuwabara K, Imanaka Y, Ishizaki T. Quality and productive efficiency in simple laceration treatment. Journal of Evaluation in Clinical Practice 2006 12(2):164-173. ; PMID: 16579825 ; DOI: 10.1111/j.1365-2753.2006.00597.x
Ishizaki T, Kai I, Imanaka Y. Self-rated health and social role as predictors for 6-year total mortality among a non-disabled older Japanese population. Archives of Gerontology and Geriatrics 2006 42(1):91-99. ; PMID: 16046010 ; DOI: 10.1016/j.archger.2005.05.002
Sekimoto M, et al. JPN Guidelines for the management of acute pancreatitis: epidemiology, etiology, natural history, and outcome predictors in acute pancreatitis. Journal of hepato-biliary-pancreatic surgery 2006 2006;13(1):10-24. ; PMID: 16463207
Hayashida K, Imanaka Y. Inequity in the price of physician activity across surgical procedures. Health Policy 2005 74(1):24-38. ; PMID: 16098409 ; DOI: 10.1016/j.healthpol.2004.12.005
Hirose M, Imanaka Y, Ishizaki T, Sekimoto M, Harada Y, Kuwabara K, Hayashida K, Oh EH, Evans SE. Profiling hospital performance of laparoscopic cholecystectomy based on the administrative data of four teaching hospitals in Japan. World Journal of Surgery 2005 29(4):429-435. ; PMID: 15770381 ; DOI: 10.1007/s00268-004-7535-9
Oh EH Imanaka Y, Evans E. Determinants of the diffusion of computed tomography and magnetic resonance imaging. International Journal of Technology Assessment in Health Care 2005 21(1):73-80. ; PMID: 15736517
Sekimoto M, Imanaka Y, Evans E, Ishizaki T, Hirose M, Hayashida K, Fukui T. Practice variation in perioperative antibiotic use in Japan. International Journal for Quality in Health Care 2004 16(5):367-373. ; PMID: 15375097 ; DOI: 10.1093/intqhc/mzh066
Ishizaki T, Imanaka Y, Oh E, Kuwabara K, Hirose M, Hayashida K, Harada Y. Association of hospital resource use with comorbidity status and patient age among hip fracture patients in Japan. Health Policy 2004 69(2):179-187. ; PMID: 15212865 ; DOI: 10.1016/j.healthpol.2003.12.018
Ishizaki T, Imanaka Y, Hirose M, Hayashida K, Kizu M, Inoue A, Sugie S. Estimation of the impact of providing outpatients with information about SARS infection control on their intention of outpatient visit. Health Policy 2004 69(3):293-303. ; PMID: 15276309 ; DOI: 10.1016/j.healthpol.2004.04.008
Sekimoto M, Asai A, Ohnishi M, Nishigaki E, Fukui T, Shimbo T, Imanaka Y. Patients' preferences for involvement in treatment decision making in Japan. BMC Family Practice 2004 5(1):1-10. ; PMID: 15053839 ; DOI: 10.1186/1471-2296-5-1
International Hospital Federation and World Health Organization. (Imanaka Y as the principal investigator for the Western Pacific Region) A Global Study on Experiences in Hospital Sector Reform: The performance of hospitals under changing socio-economic conditions. WHO 2003
Ishizaki T, Kai I, Kobayashi Y, Matsuyama Y, Imanaka Y. The effect of aging on functional decline among older Japanese living in a community: a 5-year longitudinal data analysis. Aging Clinical and Experimental Research 2004 16(3):233-239. ; PMID: 15462467
Hirose M, Imanaka Y, Ishizaki T, Evans E. How can we improve the quality of health care in Japan? Learning from JCQHC hospital accreditation. Health Policy 2003 66(1):29-49 ; PMID: 14499164
Imanaka Y. Macro and micro costing of atherosclerosis-related diseases in the Japanese health care system. Atherosclerosis. 2003 4(2):189-190.
Ishizaki T, Yoshida H, Kumagai S, Watanabe S, Shinkai S, Suzuki T, Shibata H, Imanaka Y. Active life expectancy based on activities of daily living for older people living in a rural community in Japan. Geriatrics and Gerontology International 2003 3:S78-S82.
Imanaka Y, Hayashida K, Nakatani I, Kuwabara K. Validation of a theory-based costing methodology through simulation in a virtual hospital: Towards a standardized model of patient-level costing with two-dimensional components. The Proceedings of 4th World Congress of International. Health Economics Association. 2003 4:54-55.
Sekimoto M, Imanaka Y. Practice variation in perioperative antibiotic prophylaxis in Japan. The Proceedings of 20th ISQua International Conference on Quality in Health Care, Dallas. 2003 20:54-55.
Hirose M, Imanaka Y, Ishizaki T, Sekimoto M, Harada Y, Kuwabara K, Hayashida K, Oh EH, Evans E. Profiling hospital performance of laparoscopic cholecystectomy based on administrative data. World journal of surgery 2003 29(4):429-35 ; PMID: 15770381 ; DOI: 10.1007/s00268-004-7535-9
Pierre Moise, Stéphane Jacobzone and the ARD-IHD Experts Group [incl. Imanaka Y, Ishizaki T, Ogawa T] OECD Study of Cross-National Differences in the Treatment, Costs and Outcomes of Ischaemic Heart Disease (OECD Health Working Papers NO.3) OECD 2003
Pierre Moise, Stéphane Jacobzone and the ARD-IHD Experts Group. OECD Study of Cross-national Differences in the Treatment, Costs and Outcomes of Ischaemic Heart Disease (OECD Health Working Papers NO.3) - Annex 1: Tables & Charts. OECD 2003
Pierre Moise, Stéphane Jacobzone and the ARD-IHD Experts Group. OECD Study of Cross-national Differences in the Treatment, Costs and Outcomes of Ischaemic Heart Disease (OECD Health Working Papers NO.3) - Annex 2: Charts. OECD 2003
Lynelle Moon, Pierre Moise, Stéphane Jacobzone and the ARD-Stroke Experts Group [incl. Imanaka Y, Ishizaki T, Ogawa T] Stroke Care in OECD Countries: A Comparison of Treatment, Costs and Outcomes in 17 Countries (OECD Health Working Papers NO.5) OECD 2003
Lynelle Moon, Pierre Moise, Stéphane Jacobzone and the ARD-Stroke Experts Group. Stroke Care in OECD Countries: A Comparison of Treatment, Costs and Outcomes in 17 Countries (OECD Health Working Papers NO.5) – Annex OECD 2003
Tokunaga J, Imanaka Y. Influences of length of stay on patient satisfaction with hospital care in Japan. International Journal for Quality in Health Care 2002 14(6):493-502. ; PMID: 12515335
Ishizaki T, Imanaka Y, Hirose M, Kuwabara K, Ogawa T, Harada Y. A first look at variations in use of breast-conserving surgery at five teaching hospitals in Japan. International Journal for Quality in Health Care 2002 14(5):411-8. ; PMID: 12389807
Rahman M, Sekimoto M, Hira K, Koyama H, Imanaka Y, Fukui T. Is Bacillus Calmette-Guerin revaccination necessary for Japanese children? Preventive Medicine 2002 35(1):70-7 ; PMID: 12079443
Akamizu T, Nakao K, Imanaka Y. Economic evaluation of female hormone replacement therapy for osteoporosis and fractures in aged women. Japanese Journal of Health Economics and Policy 2002 11:23-42.
Ishizaki T, Kai I, Kobayashi Y, Imanaka Y. Functional transitions and active life expectancy for older Japanese living in a community. Archives of Gerontology and Geriatrics 2002 35(2):107-20. ; PMID: 14764349
Hayashida K, Nagasue I, Fukuda T, Gunji A. The natural history model of hepatitis C virus infection and the economic evaluation of alpha interferon treatment. Journal of Epidemiology 2002 12(1):22-32. ; PMID: 11848181
Ishizaki T. Maintaining and improving health status in an aged society. Aging and Health: An International Symposium
Jee-Hughes M, Jacobzone S with the OECD study collaborative expert group. OECD study of cross-national differences in the treatment, costs and outcomes of breast cancer. OECD 2001 (web site)
WHO Study WPRO Expert Group (Imanaka Y as the principal investigator for the Western Pacific Region). Hospitals within healthcare systems: Their capacity to meet the needs of populations - Western Pacific Region. WHO 2001
The Technological Change in Health Care Research Network [incl. Imanaka Y]. Differences in technological change around the world: Evidence from heart attack care. Health Affairs 2001 20(3):25-42.
Ishizaki T, Watanabe S, Suzuki T, Shibata H, Haga H. Predictors for functional decline among nondisabled older Japanese living in a community during a 3-year follow-up. Journal of the American Geriatrics Society 2000 48(11):1424-9. ; PMID: 11083318
Tokunaga J, Imanaka Y, Nobutomo K. Effects of patient demands on satisfaction with Japanese hospital care. International Journal for Quality in Health Care 2000 12(5):395-401. ; PMID: 11079219
Imanaka.Y. Casemix refinement by extracting and integrating multi-dimensional severity information from routine data. Casemix Quarterly 2000 2:21-24. (PDF)

[Asterisk * indicates research commissioned by international agencies.]