Annals of Clinical Epidemiology
Online ISSN : 2434-4338
Advance online publication
Displaying 1-15 of 15 articles from this issue
  • Atsushi Miyawaki, John N. Mafi, A. Mark Fendrick, Yusuke Tsugawa
    Article ID: 26013
    Published: 2025
    Advance online publication: December 05, 2025
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    This narrative review summarizes the concepts of low- and no-value care (LNVC), the drivers behind them, and potential strategies for de-implementation, all with a particular focus on influential conceptual and empirical research. Low-value care (LVC) refers to healthcare services for which the costs outweigh the potential benefits, while no-value care (NVC) is a narrower definition that refers to healthcare services that provide no net clinical benefit for patients (regardless of the costs). A growing global body of research shows that LNVC is widespread and imposes substantial societal costs. Mitigating the provision of such care would reduce avoidable healthcare expenditures, improve the quality and safety of treatment by minimizing overdiagnosis and overtreatment, and improve overall health by reallocating resources to high-value care. LNVC arises from interrelated factors at the system, individual-provider, and consumer-demand levels, including system incentives, industry promotion, patient expectations, and physicians’ knowledge, habits, and fears. Despite increasingly intense efforts to address LNVC, several challenges persist in terms of identification, measurement, and intervention. Multicomponent interventions targeting healthcare providers have been shown to be effective at reducing LNVC from the supply side; such interventions may include recommendations from professional societies, quality metrics for LNVC, quality-improvement initiatives, clinical decision-support tools, and payment reforms (e.g., global budgets, prior authorizations, coverage policy). Given the uneven provision of LNVC, targeted strategies centered on high-volume providers could improve the efficiency of interventions. Importantly, eliminating NVC represents a clear and actionable starting point to facilitate coordinated, multi-level efforts and collaboration among a diverse range of stakeholders.

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  • Jun Morinaga, Sayaka Shimizu, Yoshikazu Miyasato, Eiji Matsunaga, Hiro ...
    Article ID: 26014
    Published: 2025
    Advance online publication: December 05, 2025
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    Background: The incidence of end-stage kidney disease (ESKD) caused by chronic kidney disease is increasing worldwide. Patients with ESKD often exhibit significant premature aging and have a higher risk of premature mortality than the general population. Here, we conducted a prospective cohort study, the Kumamoto Hemodialysis Cohort Study, to explore the mechanisms of the premature aging phenotype exhibited by these patients using biological markers and highly detailed clinical information in a real-world setting.

    Methods: This multicenter prospective cohort study targeted adult outpatients receiving maintenance hemodialysis therapy in Kumamoto Prefecture, Japan. After enrollment, the patients were followed up for 10 years. Data were collected from the electronic medical records of medical facilities that participated retrospectively and prospectively from January 1, 2017. Clinical information was collected from electronic medical records, medical chart reviews, and patient-completed questionnaires. Serum and plasma samples were collected every 3 years. Thus far, 1,241 patients have been enrolled in this study, and we found the median age of the participants was 69 years, and 67.5% were male. Among the primary causes of kidney failure, diabetic nephropathy accounted for 38.6% of all cases, followed by glomerulonephritis (27.2%) and nephrosclerosis (9.9%). The median hemodialysis vintage was 5.8 years.

    Conclusion: This study contributes to the characterization of a premature aging phenotype together with morbidity and mortality of patients with ESKD, thereby providing insights into the prevention of the onset of premature aging-related diseases in patients receiving maintenance hemodialysis therapy.

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  • Takaomi Kobayashi, Yuichiro Nishida, Takuma Furukawa, Chisato Shimanoe ...
    Article ID: 26009
    Published: 2025
    Advance online publication: December 02, 2025
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    Background: This study aimed to validate self-reported fractures in the Japan Multi-Institutional Collaborative Cohort (J-MICC).

    Methods: Of the 10,332 participants who were followed up for 10 years, 1,137 individuals with self-reported fractures were included. Among them, 201 individuals were randomly selected, and 192 individuals with available medical records were analyzed. A false-positive fracture was defined as a self-reported fracture without a clinical diagnosis or record. We calculated the positive predictive value (PPV) stratified by the number of years from injury to response. Multivariate logistic regression analysis was used to elucidate the factors influencing false-positive fractures and to calculate the odds ratios (ORs) with 95% confidence intervals (CIs). The dependent variable was false-positive fractures, and the independent variables included factors such as fracture site, age, sex, body mass index, education, multisite fractures, multiple fractures, and number of years from injury to response.

    Results: The average age at the time of injury was 69.6 years (range, 50–80 years), and 48 individuals (25.0%) were male. Fractures were reported in the spine (41 individuals, 21.4%), upper limbs (57 individuals, 29.7%), lower limbs (71 individuals, 37.0%), and other locations (23 individuals, 11.9%), respectively. The PPV was 85.4% (164/192 individuals; 95% CI, 79.7–89.7) and was > 90% if the period from injury to response was within 3 years. False-positive fractures were significantly associated with a period from injury to response >3 years (OR, 3.46; 95% CI, 1.43–8.37).

    Conclusions: Self-reported fractures are useful outcomes; however, recall periods >3 years may increase the risk of misclassification.

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  • Masaki Hatano, Yusuke Sasabuchi, Koji Yamada, Shotaro Aso, Hisatoshi I ...
    Article ID: 26010
    Published: 2025
    Advance online publication: December 02, 2025
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    Background: This study aimed to evaluate the association of the initial body weight-stratified cefazolin antimicrobial prophylaxis (AMP) dose and surgical-site infection (SSI) in major orthopedic implant surgery.

    Methods: This nationwide, retrospective cohort study used data from the Diagnosis Procedure Combination database. We included patients (age ≥18 years) who underwent major orthopedic implant surgery between July 2010 and March 2022. Patients underwent surgery with an initial cefazolin dose of either 1 g (1 g cefazolin group) or 2 g (2 g cefazolin group). Primary outcome was in-hospital SSI. Restricted cubic spline functions were used to estimate the nonlinear association of body weight-stratified cefazolin dose with the outcome and between cefazolin dose per weight and the outcome.

    Results: Among the 408,487 participants, 394,731 and 13,756 were in the 1 g and 2g cefazolin groups, respectively. The 1 g cefazolin group, but not the 2 g cefazolin group, showed a J-shaped relationship between body weight and SSI, which increased continuously beyond 50 kg, in an increased risk of SSI with body weight. A reverse J-shaped relationship was observed between cefazolin dose per weight and SSI, with an increased risk of SSI at <20 mg/kg.

    Conclusion: An increased risk of SSI was observed with 1 g cefazolin, but not with 2 g cefazolin, as an initial AMP with higher body weight among adults weighing >50 kg.

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  • Hayato Yamana, Sachiko Ono, Nobuaki Michihata, Kohei Uemura, Hideo Yas ...
    Article ID: 26011
    Published: 2025
    Advance online publication: December 02, 2025
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    Background

    In 1986, a strategy of vaccinating infants at 2, 3, and 5 months of age was implemented in Japan to prevent the vertical transmission of the hepatitis B virus. This strategy was revised in 2013 to vaccinate infants at birth, 1 month, and 6 months of age. We aimed to evaluate the effect of this policy change on the vaccination status of infants born to mothers with positive hepatitis B surface antigen.

    Methods

    We identified infants born between April 2009 and March 2021 from the JMDC Claims Database. Administration of hepatitis B immunoglobulin at birth was used to identify infants who received preventive measures against vertical transmission. The timing of hepatitis B vaccine administration within 12 months of birth was compared between old (born between April 2009 and September 2013) and new (born between October 2013 and March 2021) groups.

    Results

    Among the 77,797 and 510,584 infants born before and after October 1 2013, respectively, 190 (0.24%) and 732 (0.14%) were analyzed. The proportion of infants receiving at least one dose of the vaccine increased from 63% to 96% (p<0.001). The proportion of infants who received timely first, second, and third doses of vaccines changed from 54% to 90% (p<0.001), 46% to 59% (p=0.002), and 39% to 31% (p=0.034), respectively.

    Conclusions

    The change in strategy against the vertical transmission of hepatitis B virus resulted in an increased rate of receiving the first dose of the vaccine and a decreased rate of timely completion of the recommended doses.

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  • Yoshihisa Miyamoto, Akira Okada, Yusuke Sasabuchi
    Article ID: 26012
    Published: 2025
    Advance online publication: December 02, 2025
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    The DeSC database, launched in 2020 by DeSC Healthcare Co., Ltd. is a commercially available Japanese administrative medical claims and health checkup database. Recently, long-term care insurance (LTCI) claims data—covering care-need levels, monthly care benefits, service utilization, and cost information—have been integrated into the database. We showed that the distributions of the seven care-need levels were highly similar between the DeSC database and the official report by the Ministry of Health, Labour and Welfare. This similarity supports the representativeness and reliability of the DeSC database for epidemiological analyses using care-need status, particularly in the Advanced Elderly Medical Service System. This integrated dataset bridges critical information gaps and offers substantial advantages for health services research and epidemiological studies through individual-level linkage of medical, pharmacy, and LTCI claims. This study provides an overview of the LTCI claims data and available data items in the DeSC database and discusses future research prospects, with a particular focus on the linkage between medical and LTCI claims.

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  • Nobuya Kitamura, Takashi Tagami, Munekazu Takeda, Koichiro Shinozaki, ...
    Article ID: 24003E
    Published: 2025
    Advance online publication: November 21, 2025
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION
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  • Takahito Morita, Yusuke Sasabuchi, Hideo Yasunaga
    Article ID: 26007
    Published: 2025
    Advance online publication: November 18, 2025
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    BACKGROUND

    In Japan, biosimilars have the potential to reduce drug expenditure because their official price is lower than the price of the original products. To promote biosimilars, the Japanese government introduced a new financial incentive scheme for medical institutions to prescribe biosimilars to outpatients in April 2020. However, the impact of the incentive remains unevaluated. Hence, in this study, we conducted an interrupted time-series analysis to evaluate the impact of the incentive scheme on biosimilar prescription.

    METHODS

    We used the DeSC database in Japan. From this database, we included 3,348 patients who required self-injection and were prescribed insulin, human growth hormone, or etanercept. Interrupted time-series analyses were conducted by fitting Prais–Winsten linear regression models to assess the association of the financial incentive with the outcomes, namely, monthly proportions of biosimilar prescriptions between April 2019 and March 2021.

    RESULTS

    No significant changes were observed in the monthly proportion of biosimilar prescriptions immediately after the introduction of the incentive. The sustained effect, representing the effect of the intervention over time, was also not significant.

    CONCLUSIONS

    Our study suggests that the financial incentive introduced in April 2020 in Japan was not associated with an increase in biosimilar prescriptions.

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  • Qiuyan Yu, Angel YS Wong
    Article ID: 26008
    Published: 2025
    Advance online publication: November 18, 2025
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    This article introduces the basic concept of a novel 6-parameter model case-crossover study with active comparator design. While case-crossover study design eliminates time-invariant confounding, the 6-parameter model as a modified version also allows studying the effect of drug initiation patterns between two interacting drugs. The implementation of the case-crossover study is illustrated, including the generation of the dataset for data analysis and performing the 6-parameter model using conditional logistic regression. Potential interpretation framework is proposed using eight combinations based on three scenarios shown in the results of the 6-parameters case-crossover study design.

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  • Yohei Hashimoto, Daniel Barthelmes, Mark Gillies
    Article ID: 26004
    Published: 2025
    Advance online publication: July 24, 2025
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    The Fight Retinal Blindness! Registry is a prospectively-designed registry developed in 2009 that collects international data on treatment outcomes for eye diseases including neovascular age-related macular degeneration, diabetic macular edema and retinal vein occlusion. The validated and high-quality data have generated significant real-world evidence regarding clinically relevant issues, such as long-term visual outcomes, dosing regimens and practitioner variation. This paper outlines the Fight Retinal Blindness! Registry, highlighting its pros and cons, and introduces some findings from the registry.

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  • Ai Ogawa, Shinji Okabayashi, Tatsuhiko Suzuki, Hiroshi Sudo, Yosuke Ya ...
    Article ID: 26005
    Published: 2025
    Advance online publication: July 04, 2025
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    Background: It remains unclear whether pharmacist-led educational programs in community pharmacies could increase appropriate ophthalmic visits for patients with diabetes. We assessed efficacy of pharmacist-led education on ophthalmology visits for diabetes.

    Methods: We conducted a cluster randomized controlled trial at 32 community pharmacies in Japan, targeting individuals with diabetes with no ophthalmic visits over a year. Pharmacists in the intervention group received online training on diabetic retinopathy and educated patients, while the control group received a pamphlet. The primary outcome was ophthalmic visits during the follow-up period. Generalized estimating equations were performed with two adjusted models: age and sex (model 1), and additionally diabetic retinopathy factors (model 2). Key secondary outcomes were changes in behavior for ophthalmic visits and glycated hemoglobin (HbA1c) levels.

    Results: Overall, 268 patients were included (133 intervention and 135 control). Participants' mean age was 60.1 years, and HbA1c level was 7.5%. Ophthalmic visits occurred in 18.8% (25/133) of the intervention and 20.7% (28/135) of the control group, yielding no significant difference (model 1, risk difference [RD] -0.03 [-0.14 to 0.08], risk ratio [RR] 0.88 (0.54 to 1.45); model 2, RD -0.07 [-0.21 to 0.08], RR 0.73 [0.41 to 1.30]). There was no significant difference between the two groups in the mean changes from baseline to 6 months in behavior for ophthalmic visits (0.07 [-0.23 to 0.37]) and HbA1c levels (-0.28 [-0.76 to 0.20]).

    Conclusions: Pharmacist-led education on diabetic retinopathy did not increase ophthalmology visits or improve diabetes-related outcomes. Effective strategies to encourage ophthalmology visits are required.

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  • Hui Yuan, Akira Okada, Hideo Yasunaga
    Article ID: 26006
    Published: 2025
    Advance online publication: July 04, 2025
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    Background This study aimed to evaluate the association between metformin use and the risk of cervical cancer in women with diabetes compared to dipeptidyl peptidase-4 inhibitors (DPP-4is), using a new-user active-comparator design.

    Methods We analyzed data from the JMDC claims database for new users of metformin or DPP-4i between 2010–2022 who were women. Propensity score overlap-weighting was applied to adjust for differences in age, complications, comorbidities, and other anti-diabetic medications. Kaplan–Meier curves and Cox proportional hazards models were used to compare cervical cancer incidence between the metformin and DPP-4i groups.

    Results A total of 31,269 eligible individuals were identified, comprising 11,466 metformin users and 19,803 DPP-4i users. Cervical cancer occurred in 11 women (34.0/100,000 person-years) from the metformin group and 34 (59.0/100,000 person-years) in the DPP-4i group. Metformin use was associated with a lower risk of cervical cancer in our unadjusted Kaplan–Meier analysis (P = 0.058), and multivariable-adjusted Cox model (hazard ratio, 0.49; 95% CI, 0.22–1.09; P = 0.082), although neither difference was statistically significant.

    Conclusions Our findings did not show a statistically significant association between metformin use and cervical cancer incidence. However, this study’s limited sample size precluded definitive conclusions.

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  • Sumire Suzuki, Tatsuhiko Suzuki, Tsukasa Kamitani, Ryohei Yamamoto
    Article ID: 26003
    Published: 2025
    Advance online publication: June 25, 2025
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    Background: Polypharmacy management represents a public health concern; however, intervention by community pharmacists remains limited. Therefore, we evaluated the effectiveness of community pharmacy-based educational intervention for improving polypharmacy management using interrupted time series analysis (ITSA).

    Methods: We conducted the ITSA of an educational intervention implemented from June to September 2021 across pharmacies under Medical System Network Co., Ltd., Japan. We analyzed pharmacy claims data from April 2020 to May 2024, with no missing values. The intervention included lectures and workshops delivered via cascade training. The primary and secondary outcomes were the number of Fee for Medication Adjustment Support 2 (FMAS2) and Fee for Medication Adjustment Support 1 (FMAS1) per 100,000 patients, respectively. FMAS2 is claimed when pharmacists propose reducing medications for patients taking six or more medications from multiple institutions, and FMAS1 is claimed when the proposal leads to actual reduction.

    Results: The study included 404 pharmacies with an average of 569,909 patients per month. After intervention, FMAS2 claims immediately increased by 3.82 per 100,000 people (95% confidence interval (CI): 1.23 to 6.41, p = 0.005), with no significant trend change. FMAS1 claims first increased by 1.29 per 100,000 people (95% CI: 0.49 to 2.09, p = 0.002) but decreased thereafter (95% CI: −0.298 to −0.130, p < 0.001).

    Conclusions: Educational intervention increased FMAS2 and FMAS1 claims in the short term. However, the clinical impact of this intervention was small, and its long-term effectiveness is limited. Future efforts should focus on developing sustainable programs and follow-up systems.

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  • Akifumi Endo, Nobuaki Michihata, Masato Yanagi, Masamune Higashigawa, ...
    Article ID: 26001
    Published: 2025
    Advance online publication: June 20, 2025
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    Background: New drugs for pediatric immune thrombocytopenia have recently been developed; however, the practice patterns of the different treatments remain unclear in Japan. Methods: Using a national inpatient database, we analyzed recent trends in the treatment practice patterns of pediatric patients with immune thrombocytopenia.

    Results: From 2010 to 2021, the proportion of corticosteroid use did not change from 35.2 to 33.4%, whereas the proportion of intravenous immunoglobulin increased from 66.0 to 76.2% (P trend 0.003), and rituximab, romiplostim, and eltrombopag increased from 0.2 to 0.7%, 0.0 to 1.4%, and 0.3 to 7.5%, respectively, (P trend <0.001, 0.003, and <0.001, respectively). The proportion of no-treatment decreased from 20.2 to 6.5% (P trend <0.001). None of the patients had undergone splenectomy since 2016. Intravenous immunoglobulin and corticosteroids were mostly used at 1.0 g/kg and 2.0 mg/kg per day, respectively. We compared clinical practice patterns and outcomes between the only one-treatment and no-treatment groups. Intravenous immunoglobulin tended to be used in non-academic hospitals and younger patients; however, more risk of readmissions within 6 months occurred. Second-line treatment tended to be used in academic hospitals and older patients.

    Conclusions: We observed an increasing trend in intravenous immunoglobulin use and second-line treatment, no change in corticosteroid use, and a decreasing trend in no-treatment approaches, using a national inpatient database. The hospital type might have affected the practice patterns. Clinicians might have chosen the optimal treatment for pediatric patients with immune thrombocytopenia considering several factors and patient backgrounds.

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  • Satoshi Kodama, Mitsuhiro Kainaga, Shotaro Aso, Taisuke Jo, Yohei Hash ...
    Article ID: 26002
    Published: 2025
    Advance online publication: June 20, 2025
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    Introduction: Miller Fisher syndrome (MFS) is typically associated with a benign course and spontaneous recovery. However, immunotherapies such as intravenous immunoglobulin (IVIG) and plasma exchange (PE) are often administered for this condition because of the potential for clinical deterioration. We aimed to evaluate the real-world use of immunotherapies in MFS management using a nationwide Japanese database.

    Methods: We conducted a retrospective cohort study between April 2014 and March 2020 using the Japanese Diagnosis Procedure Combination database. Patient demographics and treatment modalities were described. Outcomes included length of hospital stay, in-hospital mortality, hospitalization cost, and activities of daily living defined by the Barthel index score.

    Results: We identified 1,595 patients with MFS. Of these, 999 (62.6%) received immunotherapy (including IVIG for 908 [56.9%] patients, intravenous methylprednisolone for 219 [13.7%] patients, and PE for 18 [1.8%] patients). In patients with and without immunotherapy, the median length of hospital stay was 18 and 12 days, in-hospital mortality was 0.7% and 0.2%, median total hospitalization costs were ¥1,660,200 and ¥549,375, and the proportions of Barthel index score of 95–100 at discharge were 75.3% and 75.2%, respectively.

    Conclusion: Our findings highlight the widespread use of immunotherapies for MFS in Japan despite its generally favorable natural course.

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