Variation in fracture risk by season and weather: A comprehensive analysis across age and fracture site using a National Database of Health Insurance Claims in Japan

Epidemiology of Angioid Streaks and Pseudoxanthoma Elasticum (2011-2020): A Nationwide Population-based Cohort Study

Purpose

We aimed to describe the epidemiology of angioid streaks (AS) and pseudoxanthoma elasticum (PXE), which are rare diseases, using a national claims database.

Design

This was a population-based longitudinal cohort study.

Participants

A total of 126 million individuals were covered by the universal health coverage system in Japan.

Methods

With permission from the Ministry of Health, Labor and Welfare, we accessed all data from the National Database of Health Insurance Claims and Specific Health Checkups of Japan, which contains the nationwide health insurance claims data for 126 million Japanese. We identified individuals with AS and PXE between January 2011 and December 2020. The incidence rates, prevalence, overlap of AS and PXE, and mean age at death were calculated.

Main Outcome Measures

The incidence rates and prevalence of AS and PXE.

Results

A total of 6598 cases of AS and 1020 cases of PXE were identified during the 10-year study period. The incidence rates of AS and PXE were 0.52 (95% confidence interval, 0.48-0.56) and 0.08 (95% confidence interval, 0.07-0.10) per 100 000 person-years, respectively. On October 1, 2020, the prevalence of AS and PXE was 6.5 (95% confidence interval, 6.38-6.66) and 0.83 (95% confidence interval, 0.78-0.89) per 100 000 persons, respectively. The overlap of AS and PXE was 363 patients. The mean age at death of individuals with AS and PXE was 79.3 ± 0.51 and 77.1 ± 2.68 years, respectively.

Conclusion

This is the first population-based study to elucidate the epidemiology of AS and PXE. The mean age of death of both AS and PXE patients was younger than the mean life expectancy of the general Japanese population, thus, appropriate diagnosis and management are important to avoid preventable death.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Annual trends of ophthalmic surgeries in Japan's super-aged society, 2014-2020: a national claims database study

This study aimed to analyze the trends and factors influencing the number of ophthalmic surgeries in Japan using the open data from the National Database of Health Insurance Claims and Specific Health Checkups of Japan published by the Ministry of Health, Labour and Welfare. We calculated the number of cataract, glaucoma, and vitreoretinal surgeries, categorized by sex, age, and surgical type, for the fiscal years (FY) 2014 to 2020. The number of cataract surgeries remained stable at approximately 1.45 million cases from FY 2014 to 2018, increased to nearly 1.6 million cases in FY 2019, and decreased to 1.45 million cases in FY 2020. Among glaucoma surgeries, surgical treatments were increased 1.8 times over 7 years, from 33,000 to 60,000 cases. Laser treatment remained steady at around 55,000 cases from FY 2014 to 2017 and then increased to approximately 60,000 cases. The number of vitreoretinal surgeries was increased 1.2 times from FY 2014 to 2019, from 120,000 to 140,000, and decreased to 130,000 by FY 2020. Trends in ophthalmic surgeries over the past 7 years may be influenced by population aging, minimally invasive surgery, and the coronavirus disease pandemic. These findings have implications on surgical decision-making and resource allocation.

Incidence of opportunistic infections in patients with rheumatoid arthritis treated with different molecular-targeted drugs: A population-based retrospective cohort study

OBJECTIVES

We compared the incidences of four opportunistic infections (OIs) in patients with rheumatoid arthritis (RA) treated with molecular-targeted drugs from big claims data.

MATERIALS AND METHODS

We identified 205,906 patients with RA who were prescribed molecular-targeted drugs in 2010-17 from the National Database of Japan and calculated the incidence of four OIs (Pneumocystis pneumonia, tuberculosis, nontuberculous mycobacterial infection, and herpes zoster).

RESULTS

The total number of Pneumocystis pneumonia, tuberculosis, nontuberculous mycobacterial infection, and herpes zoster patients with biological disease-modifying antirheumatic drugs or tofacitinib treatment history in RA was 765, 1158, 834, and 18,336, respectively. The incidence rates of each OI for all biological disease-modifying antirheumatic drugs were 0.14, 0.14, 0.09, and 2.40 per 100 person-years, respectively, while for tofacitinib they were 0.22, 0.22, 0.07, and 7.00 per 100 person-years. No big difference was observed among biological disease-modifying antirheumatic drugs. All OIs showed higher incidence in those >65 years, but Pneumocystis pneumonia, nontuberculous mycobacterial infection, and herpes zoster showed no difference between those 65-74 years old and those >75 years old. The median of occurrence was the third, seventh, ninth, and thirteenth month after treatment, respectively.

CONCLUSIONS

We counted real incidence rates of OIs for the whole nation from big claims data.

Statin persistence and adherence among older initiators: A nationwide cohort study using the national health insurance claims database in Japan

PURPOSE

This study clarifies the reality of persistence and adherence to statins in older Japanese people who initiated statin use and compares it between primary and secondary prevention cohorts.

METHODS

The nationwide study using the national claims database targeted statin initiators aged ≥55 years from FY2014 to FY2017 in Japan. Persistence and adherence to statins were analyzed overall and according to subgroups based on sex, age stratum, and prevention cohorts. Permissible gap of median days that statins were supplied per prescription to an individual was employed. Persistence rates were estimated as Kaplan-Meier estimates. Poor adherence during persistence was evaluated and defined as <0.8 of the proportion of days covered.

RESULTS

Of 3 675 949 initiators, approximately 80% initiated statin use with strong variants. The persistence rate at 1 year was 0.61. Poor adherence to statins during persistence was 8.0% in all patients and this value gradually improved with increasing age. Persistence rate and adherence were lower for the primary prevention cohort than for the secondary prevention cohort, and a notable sex difference was observed for the secondary prevention cohort, which was lower in females but was almost never and slightly observed in the primary prevention cohorts without and with high-risk factors, respectively.

CONCLUSIONS

Many statin initiators discontinued statins shortly following statin initiation but adherence while on statin therapy was good. Attentively watching older patients not to discontinue statins and listening to their reasons for discontinuation are required, especially for initiators in primary prevention and females in secondary prevention.

Virtual patient identifier (vPID): Improving patient traceability using anonymized identifiers in Japanese healthcare insurance claims database

Objective

Japan's national-level healthcare insurance claims database (NDB) is a collective database that contains the entire information on healthcare services being provided to all citizens. However, existing anonymized identifiers (ID1 and ID2) have a poor capability of tracing patients' claims in the database, hindering longitudinal analyses. This study presents a virtual patient identifier (vPID), which we have developed on top of these existing identifiers, to improve the patient traceability.

Methods

vPID is a new composite identifier that intensively consolidates ID1 and ID2 co-occurring in an identical claim to allow to collect claims of each patient even though its ID1 or ID2 may change due to life events or clerical errors. We conducted a verification test with prefecture-level datasets of healthcare insurance claims and enrollee history records, which allowed us to compare vPID with the ground truth, in terms of an identifiability score (indicating a capability of distinguishing a patient's claims from another patient's claims) and a traceability score (indicating a capability of collecting claims of an identical patient).

Results

The verification test has clarified that vPID offers significantly higher traceability scores (0.994, Mie; 0.997, Gifu) than ID1 (0.863, Mie; 0.884, Gifu) and ID2 (0.602, Mie; 0.839, Gifu), and comparable (0.996, Mie) and lower (0.979, Gifu) identifiability scores.

Discussion

vPID is seemingly useful for a wide spectrum of analytic studies unless they focus on sensitive cases to the design limitation of vPID, such as patients experiencing marriage and job change, simultaneously, and same-sex twin children.

Conclusion

vPID successfully improves patient traceability, providing an opportunity for longitudinal analyses that used to be practically impossible for NDB. Further exploration is also necessary, in particular, for mitigating identification errors.

The association between weather warnings and hip fractures in the Republic of Ireland

This study examined the relationship between hip fractures and weather warnings with the hypothesis higher rates of fractures occur during warnings. National hip fracture database and weather warning records were utilised. Higher rates of hip fractures were found with severe warnings. This has implications for planning in future severe warnings.

BACKGROUND

Hip fractures represent a significant burden on the Irish Health system with 3666 in 2020. The Irish National Meteorological Service operates a colour coded warning system. Yellow being least severe, while orange represents weather with capacity to impact individuals in affected areas and red represents advice to protect themselves and property. Previous studies investigated the seasonality of hip fractures, which remains but none have investigated the relationship between weather warnings and rates of hip fractures. The hypothesis was that increasing weather warnings would be associated with increased hip fractures. The aim was to investigate the relationship between weather warnings and hip fractures in the Republic of Ireland.

METHODS

Comparison of national weather warning archives from 2013 to 2019 to Fracture Database records. Reviews assessed whether fractures occurred on days a weather warning was in place in the individual's local county. A statistical analysis of warning features and their relationship to hip fractures was then performed. Fractures and weather warnings were stratified by county with both a panel and case crossover analysis performed.

RESULTS

There was a tendency towards increased incidence of hip fractures with weather warnings in adjusted analysis (IRR 1.02; 95%CI 0.99-1.06; p-value 0.123). Orange warnings were associated with a statistically higher incidence of fractures (IRR 1.06; 1.01-1.12; p-value 0.026). In both panel and case crossover analysis, both orange and yellow warnings were associated with fractures. Red warnings were associated with a lower incidence of fracture on day of warning (adjusted incidence rate ratio 0.92; 0.70-1.22; p-value 0.569) but a higher incidence on the following day (adjusted incidence rate ratio 1.14; 0.88-1.46; p-value 0.313).

CONCLUSION

An increased incidence of hip fractures appears to occur during weather warnings. Consideration should be given when preparing for periods of extreme weather, ensuring sufficiently resources.

Pediatric anesthesia practices during the COVID‐19 pandemic: A retrospective cohort study

Background and Aims

The onset of the coronavirus 2019 (COVID‐19) pandemic brought together the American Society of Regional Anesthesia and Pain Medicine (ASRA) and the European Society of Regional Anaesthesia and Pain Therapy (ESRA) to release a joint statement on anesthesia use. Their statement included a recommendation to use regional anesthesia whenever possible to mitigate the risk associated with aerosolizing procedures. We sought to examine the utilization of anesthesia in pediatric patients undergoing a surgical procedure for fractures or ligament repairs before and during COVID‐19.

Methods

Using the Premier Health Database, we retrospectively analyzed pediatric patients undergoing a surgical intervention for fractures or ligament repair before and during COVID‐19. We sought to determine if there were differences in anesthesia use among this cohort during the two time periods. Fracture groups included shoulder and clavicle, humerus and elbow, forearm and wrist, hand and finger, pelvis and hip, femur and knee, leg and ankles, and foot and toes. Ligament procedures included surgical intervention for the anterior cruciate ligament and ulnar collateral ligament repair.

Results

We identified a total of 5935 patients undergoing a surgical procedure for fractures or ligament repairs before and during COVID‐19. After exclusion for unknown anesthesia use, 2,807 patients were included in our cohort with 81.5% (n = 2288) of patients undergoing a procedure under general anesthesia, 6.4% (n = 181) under regional anesthesia, and 12.0% (n = 338) under combined general‐regional anesthesia. There did not appear to be a significant difference in the type of anesthesia used before and during COVID‐19 (p = 0.052).

Conclusions

Our study did not identify a difference in anesthesia use before and during COVID‐19 among pediatric patients undergoing a surgical procedure. Further studies should estimate the change in anesthesia used during the time period when elective procedures were resumed.

Traumatic Proximal Femoral Fractures during COVID-19 Pandemic in the US: An ACS NSQIP® Analysis

In order to determine the impact of COVID-19 on the treatment and outcomes in patients with proximal femoral fracture’s (PFF), we analyzed a national US sample. This is a retrospective review of American College of Surgery’s (ACS) National Surgical Quality Improvement Program (NSQIP) for patients with proximal femoral fractures. A total of 26,830 and 26,300 patients sustaining PFF and undergoing surgical treatment were sampled during 2019 and 2020, respectively. On multivariable logistic regression, patients were less likely to have ‘presence of non-healing wound’ (p < 0.001), functional status ‘independent’ (p = 0.012), undergo surgical procedures of ‘hemiarthroplasty’(p = 0.002) and ‘ORIF IT, Peritroch, Subtroch with plates and screws’ (p < 0.001) and to be ‘alive at 30-days post-op’ (p = 0.001) in 2020 as compared to 2019. Patients were more likely to have a case status ‘emergent’, ‘loss of ≥10% body weight’, discharge destination of ‘home’ (p < 0.001 for each) or ‘leaving against medical advice’ (p = 0.026), postoperative ‘acute renal failure (ARF)’ (p = 0.011), ‘myocardial infarction (MI)’ (p = 0.006), ‘pulmonary embolism (PE)’ (p = 0.047), and ‘deep venous thrombosis (DVT)’ (p = 0.049) in 2020 as compared to 2019. Patients sustaining PFF and undergoing surgical treatment during pandemic year 2020 differed significantly in preoperative characteristics and 30-day postoperative complications when compared to patients from the previous year.

The impact of COVID-19 restrictions on participant enrollment in the PREPARE trial

Background

At the initiation of the COVID-19 pandemic, restrictions forced researchers to decide whether to continue their ongoing clinical trials. The PREPARE (Pragmatic Randomized Trial Evaluating Pre-Operative Alcohol Skin Solutions in Fractured Extremities) trial is a pragmatic cluster-randomized crossover trial in patients with open and closed fractures. PREPARE was enrolling over 200 participants per month at the initiation of the pandemic. We aim to describe how the COVID-19 research restrictions affected participant enrollment.

Methods

The PREPARE protocol permitted telephone consent, however, sites were obtaining consent in-person. To continue enrollment after the initiation of the restrictions participating sites obtained ethics approval for telephone consent scripts and the waiver of a signature on the consent form. We recorded the number of sites that switched to telephone consent, paused enrollment, and the length of the pause. We used t-tests to compare the differences in monthly enrollment between July 2019 and November 2020.

Results

All 19 sites quickly implement telephone consent. Fourteen out of nineteen (73.6%) sites paused enrollment due to COVID-19 restrictions. The median length of enrollment pause was 46.5 days (range, 7–121 days; interquartile range, 61 days). The months immediately following the implementation of restrictions had significantly lower enrollment.

Conclusion

A pragmatic design allowed sites to quickly adapt their procedures for obtaining informed consent via telephone and allowed for minimal interruptions to enrollment during the pandemic.

Seasonality in hip fracture among hemodialysis patients and kidney transplant recipients in South Korea

BACKGROUND

The seasonality of hip fracture in hemodialysis (HD) patients and kidney transplant recipients (KTRs) have not been reported. We assessed seasonal variations in hip fractures among patients with end-stage kidney disease who undergo maintenance HD and KTRs.

METHODS

Using the Korean National Health Insurance System database from January 2012 to December 2017, monthly counts of hip fracture were calculated among HD patients (n = 77,420) and KTRs (n = 8,921). The 6-year normalized monthly fraction and seasonal fractions of hip fractures were calculated. A cosinor analysis was performed to determine the seasonality of the monthly incidence of hip fractures.

RESULTS

The 6-year average monthly fraction of hip fractures was lowest in June and highest in October in HD patients, and lowest in February and highest in November in KTRs. The 6-year average seasonal fraction among HD patients was lowest in summer and highest in winter, and lowest in summer and highest in autumn among KTRs, but there was no significant difference. The incidence ratio of hip fractures was lowest in June and highest in January in HD patients, and lowest in August and highest in November in KTRs. On cosinor analysis, HD patients showed significant seasonality in hip fracture incidence, with a trough in summer and a peak in winter (P = 0.031), whereas KTRs did not exhibit a significant trend (P = 0.44).

CONCLUSION

Hip fractures occurred more frequently in winter and less frequently in summer in patients undergoing HD, whereas KTRs did not show a seasonal trend.

Secular trends in incidence and seasonal variation of distal radius fracture among children: A nationwide study based on the Swedish National Patient Register 2002-2016

BACKGROUND AND PURPOSE

Although distal radius fracture (DRF) is the most common fracture type in children, research on its seasonality across different age groups is limited. We investigated secular trends in incidence and seasonal variation of pediatric DRF based on Swedish nationwide population database.

PATIENTS AND METHODS

In this observational study, data for all children aged <18 years in Sweden with DRF defined by ICD-codes were analyzed for each month and each year during 2002-2016 using the Swedish National Patient Register. The general population counts for each age and sex-category were acquired to evaluate population at risk for each period. We calculated the age standardized and sex specific annual incidence rates, seasonal incidence rates, and monthly incidence rates and analyzed the seasonal variation in the mechanisms of injury.

RESULTS

A total of 155,891 DRF cases were identified. The age standardized and sex specific incidence rate was 531 (95%CI 528-533) per 100,000 patient years at risk. Fracture risk was highest during summer and lowest in the winter. The highest seasonal variation was observed among boys 2- < 5 years. The crude incidence rate and the age-standardized incidence rates in winter significantly decreased between 2002 and 2016 (annual percentage change, -2 %).

INTERPRETATION

We found significant seasonal variation in DRF among all age groups in Swedish children. The findings can help in developing strategies to prevent fractures as well as in allocating medical and social resources.

Seasonally Dependent Change of the Number of Fractures after 50 Years of Age in Poland-Analysis of Combined Health Care and Climate Datasets

Aim: The incidence of fractures correlates with many independent and interrelated factors. The aim of the study was to examine trends in fracture incidence and to find possible reasons for changes. Materials and methods: A complete dataset of Polish population aged above 50 from the National Heath Fund—which is a single, state-owned payer for the health service procedures in Poland—covering the years between 2010 and 2015 was analyzed along with climate dataset. Results: The analysis indicated that there was a substantial and statistically significant decrease in the incidence of forearm and hip fractures (p = 0.007 and 0.007, respectively). On the other side, there was a statistically significant increase in incidence of humerus and lumbar fractures (p = 0.002, p < 0.001, respectively). The observed changes (especially decrease in forearm and hip fracture incidence) happened mostly in the cold season and were correlated to mean-temperature changes during the assessed time period. Conclusion: In the analysis based on the dataset obtained from fracture-related database collected in Poland in the years 2010−2015 in the population of patients over 50 years of age, we observed that the changes of fracture incidence during the observation period are associated with and may be dependent on the season (warmer versus colder) and on mean temperature increase during the observation period.

Medical expenditures for fragility hip fracture in Japan: a study using the nationwide health insurance claims database

Using the nationwide health insurance claims database in Japan, we estimated total annual medical expenditures for fragility hip fracture across the population at 329.2 billion yen (2.99 billion US dollars). Long-term care expenditures were not included. Fragility hip fracture imposes a considerable health economic burden on society in Japan.

PURPOSE

Fragility hip fracture imposes a substantial health economic burden on society globally. We aimed to estimate medical expenditures for fragility hip fracture using the nationwide health insurance claims database in Japan.

METHODS

We included adults aged 60 and over without prior hip fracture who were admitted for fragility hip fracture (i.e., femoral neck or extracapsular) between October 2014 and October 2015 (13 months). Fragility hip fracture was identified through newly assigned disease codes for fracture and procedure codes associated with the fracture. As a proxy for medical expenditures per patient, incremental payments were calculated (i.e., the difference between the total payments 6 months before and after fragility hip fracture). The total payments included health insurance reimbursements and copayments for inpatient and outpatient services. Long-term care expenditures were not included in this study.

RESULTS

We identified 142,361 individuals (28,868 male and 113,493 female) with fragility hip fracture. Mean medical expenditures for fragility hip fracture per patient were 2,550,000 yen (¥) (23,180 US dollars [$]; ¥110 = $1) in male and ¥2,494,000 ($22,670) in female patients, respectively. Total annual medical expenditures for fragility hip fracture across the population were 329.2 billion yen (2.99 billion US dollars): 67.96 billion yen (620 million US dollars) in male and 261.24 billion yen (2.37 billion US dollars) in female patients, respectively.

CONCLUSION

This is the first study to estimate medical expenditures for hip fracture using the nationwide health insurance claims database, which represents almost all health insurance claims in Japan. Fragility hip fracture inflicts a considerable health economic burden on society in Japan.

The Age of Death in Japanese patients with type 2 and type 1 diabetes: A descriptive epidemiological study

This study clarified the age of death in patients with or without diabetes using the largest health insurance database in Japan. This population‐based retrospective cohort study was performed using the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) data. The ages of death between people with and without diabetes were compared. A total of 142,277,986 patients (74,488,962 women and 67,789,024 men) over 6 years, including 4,647,016 females, and 6,507,817 males with diabetes, were included. 2,786,071 females and 2,975,876 males died over 6 years, including 652,699 females and 954,655 males with diabetes. The average age of death in patients with diabetes was 2.6 years less than that of patients without diabetes. This descriptive epidemiological study illustrated the difference in age at death of patients with and without diabetes.

Evaluation of adrenaline auto-injector prescription profiles: A population-based, retrospective cohort study within the National Insurance Claims Database of Japan

BACKGROUND

Adrenaline is the first-line medication for managing anaphylaxis. A better understanding of prescription trends for adrenaline auto-injectors (AAIs) is important to improving patient care as well as information on health education interventions and medical guidelines. However, it has been difficult to gather comprehensive data in a sustainable manner. Thus, we aimed to investigate trends in AAI prescriptions in Japan.

METHODS

We searched the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB), a unique and comprehensive database of health insurance claims, and investigated prescriptions for AAIs for all ages (April 2017 to March 2018). We assessed the annual number of prescriptions per person as well as prescription rates per 100,000 population per year by age, sex, and geographic region.

RESULTS

A total of 88,039 subjects (56,109 males, 31,930 female) and 116,758 devices (1.33 AAIs per patient per year) were prescribed AAIs at least once a year for all ages. The prescription rate for AAIs was 69.5 per 100,000 population-years. Patients aged 0-9 years were prescribed AAIs at the rate of 278.9 per 100,000 population-years. Patients aged 0-19 years were 6.4 times more likely to be prescribed AAIs than those over 20 years of age. Males were more frequently prescribed AAIs than females in all age groups, except for those aged 20-24 years. We also evaluated differences in prescription rates by geographic region.

CONCLUSIONS

This comprehensive evaluation revealed trends in AAI prescriptions, thus helping develop preventive strategies with respect to anaphylaxis in Japan.

Tracing all patients who received insured dialysis treatment in Japan and the present situation of their number of deaths

Background

The survival rate of chronic dialysis patients in Japan remains the highest worldwide, so there is value in presenting Japan’s situation internationally. We examined whether aggregate figures on dialysis patients in the National Database of Health Insurance Claims and Special Health Checkups of Japan (NDB), which contains data on insured procedures of approximately 100 million Japanese residents, complement corresponding figures in the Japanese Society for Dialysis Therapy Renal Data Registry (JRDR).

Methods

Subjects were patients with medical fee points for dialysis recorded in the NDB during 2014–2018. We analyzed annual numbers of dialysis cases, newly initiated dialysis cases– and deaths.

Results

Compared with the JRDR, the NDB had about 6–7% fewer dialysis cases but a similar number of newly initiated dialysis cases. In the NDB, the number of deaths was about 6–10% lower, and the number of hemodialysis cases was lower, while that of peritoneal dialysis cases was higher. The cumulative survival rate at dialysis initiation was approximately 6 percentage points lower in the NDB than in the JRDR, indicating that some patients die at dialysis initiation. Cumulative survival rate by age group was roughly the same between the NDB and JRDR in both sexes.

Conclusion

The use of the NDB enabled us to aggregate data of dialysis patients. With the definition of dialysis patients used in this study, analyses of concomitant medications, comorbidities, surgeries, and therapies will become possible, which will be useful in many future studies.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10157-021-02163-z.

Epidemiology of childhood fractures in Israel during 2000-2019

BACKGROUND

Differences have been reported in incidence rates of fractures in the pediatric population, between countries and over time. The aim of this study was to evaluate the incidence and characteristics of fractures over 20 years among Israeli children.

METHODS

Incidence rates of fractures were derived from the electronic database of Meuhedet Health Services, a health maintenance organization providing healthcare services to 1.2 million people in Israel. Demographic and clinical data were extracted of all the fractures in individuals aged <18 years during 2000-2019. Fracture sites were determined according to ICD9 definitions. Fracture data were analyzed by age, sex, season and sector (general Jewish population, ultra-orthodox Jews and Arabs).

RESULTS

During the study period 188,283 fractures occurred in 142,049 individuals. The most common were fractures of the upper limb (65%), followed by fractures of the lower limb [20%]. The overall fracture rate was 251 per 10,000 person- years (PY), and was higher for boys than girls (319 vs. 180 per 10,000 PY, p < 0.001). During 20 years, standardized fracture rates decreased significantly in the general Jewish population, among both boys (from 457 to 325 per 10,000 PY, p < 0.001) and girls (from 244 to 196 per 10,000 PY, p < 0.001); increased among ultra-orthodox Jewish boys (from 249 to 285 per 10,000 PY, p = 0.002) and girls (from 147 to 194 per 10,000 PY, p < 0.001); and did not change significantly among Arab boys and girls. The fracture rate peaked among girls aged 10-11 years and among boys aged 12-13 years. Seasonal variation showed a bimodal distribution with peaks during spring and autumn.

CONCLUSIONS

The incidence of pediatric fractures is affected by age, gender, sector and season. Recognition of fracture characteristics may help identify specific populations and conditions for targeted prevention strategies.

Prevalence, Incidence Rate, and Risk Factors of Medication-Related Osteonecrosis of the Jaw in Patients With Osteoporosis and Cancer: A Nationwide Population-Based Study in Japan

PURPOSE

Medication-related osteonecrosis of the jaw (MRONJ) is a rare but severe adverse event of antiresorptive agents. However, the precise prevalence and factors associated with the development of MRONJ remain unknown. The present study was performed to describe the prevalence, incidence rate, and risk factors of developing MRONJ.

METHODS

We conducted a population-based retrospective cohort study using the National Database of Health Insurance, an administrative claims database of all patients in Japan. We identified patients who newly began using antiresorptive drugs from April 2015 to December 2018. The primary outcome was the development of MRONJ. We calculated the prevalence and incidence rate of MRONJ and performed a time-dependent Cox proportional hazard regression analysis to examine risk factors for developing MRONJ.

RESULTS

We identified 2,819,310 patients who newly used antiresorptive drugs during the study period. Of these patients, 2,664,104 (94.5%) had osteoporosis and 155,206 had cancer. Among the patients with osteoporosis, 1,603 (0.06%) developed MRONJ; the incidence rate was 22.9 per 100,000 person-years. Among the patients with cancer, 2,274 (1.47%) developed MRONJ; the incidence rate was 1,231.7 per 100,000 person-years. The occurrence of MRONJ was associated with poor oral conditions (including tooth extraction), age, male sex, drug type, concomitant drug use, comorbidities, cancer type, and geographic location.

CONCLUSIONS

The overall prevalence and incidence rate were low, but they were still higher than those in previous studies. Poor oral conditions were more closely related to the development of MRONJ than other factors. These findings suggest that improving poor oral hygiene may be essential to prevent MRONJ.

Trend in Prescription and Treatment Retention of Molecular-Targeted Drugs in 121,131 Japanese Patients With Rheumatoid Arthritis: A Population-Based Real-World Study

OBJECTIVES

To describe the real-world prescription and treatment retention of molecular-targeted drugs for rheumatoid arthritis (RA) in Japan.

MATERIALS AND METHODS

204,416 patients with RA prescribed at least one of the eight molecular-targeted drugs in 7 years from the National Database of Health Insurance Claims and Specific Health Checkups of Japan covering 98.3% of the Japanese population. The retention rate of each drug as well as head-to head comparisons were estimated by Kaplan-Meier method.

RESULTS

121,131 RA patients were prescribed any molecular-targeted drug for the first time, while 36,633 uses of molecular-targeted drug switched from another (switch use). The overall retention rates of molecular-targeted drugs at 12, 36, and 60 months were 0.64, 0.42, and 0.32 for the naïve use and 0.59, 0.40, and 0.31 for the switch use, respectively. Non-tumor necrosis factor (TNF)-inhibitor molecular-targeted drugs, particularly tocilizumab and tofacitinib, had higher retention rates than TNF inhibitors for both naïve and switch uses regardless of the previous drug, and showed higher retention rates in head-to-head comparisons between eight molecular-targeted drugs.

CONCLUSIONS

Our data reveal that the real-world drug retention is overall lower than previously reported and higher with non-TNF inhibitors than with TNF inhibitors.

Increase in Achilles Tendon Rupture Surgery in Japan: Results From a Nationwide Health Care Database

Background:

Nationwide epidemiologic studies in Scandinavian countries have shown that the incidence of Achilles tendon ruptures (ATRs) has increased, and the rate of surgical treatment has declined markedly in the past decade. However, there is a lack of national-level data on the trend of ATRs and surgical procedures in other regions.

Purpose:

To clarify the trend in the incidence of ATRs and the proportion of surgery using the nationwide health care database in Japan.

Study Design:

Descriptive epidemiology study.

Methods:

Age- and sex-stratified data on the annual number of ATRs and surgical procedures between 2010 and 2017 were obtained from the Japanese national health care database, which includes almost all inpatient and outpatient medical claims nationwide. The Japanese population data were also obtained from the population census. The change in the annual incidence of ATRs per 100,000 people was assessed using a Poisson regression analysis. The trend in the annual proportion of surgeries relative to the occurrence of tendon ruptures was determined using a linear regression analysis.

Results:

A total of 112,601 ATRs, with men accounting for 67%, were identified over 8 years. Patients aged ≥60 years accounted for 27,106 (24%), while those aged 20 to 39 years and 40 to 59 years accounted for 36,164 (32%) and 49,331 (44%), respectively. The annual incidence of ATR ranged from 12.8/100,000 to 13.9/100,000 (women, 8.2-8.9/100,000; men, 17.2-19.5/100,000), which did not change over the study period (P = .82). Moreover, the annual incidences did not change across sexes and age categories. The annual proportion of surgery increased significantly, from 67% in 2010 to 72% in 2017 (P = .003). The annual proportions increased across sexes and age categories except for women aged 40 to 59 years.

Conclusion:

The incidence of ATR did not change between 2010 and 2017, according to the Japanese nationwide health care database. Furthermore, the proportion of surgical treatment increased during the study period. Overall, 70% of patients underwent surgical treatment. This study suggested that the trend in ATR and surgery differed across regions.

Association between influenza and the incidence rate of new-onset type 1 diabetes in Japan

AIM

This study aimed to determine whether there is an association between influenza and new-onset type 1 diabetes.

MATERIALS AND METHODS

This population-based retrospective cohort study used data from the National Database of Health Insurance Claims and Specific Health Check-ups of Japan. Influenza was defined based on drug prescriptions and the onset of type 1 diabetes was defined using specific medical codes indicating a diagnosis of type 1 diabetes. The incidence rate ratio of new-onset type 1 diabetes within 180 days after an influenza diagnosis was calculated and it was compared with that at other times using Poisson regression and generalized estimating equations. Sensitivity analyses were performed to confirm the robustness of this finding.

RESULTS

The data of 10,400 patients with new-onset type 1 diabetes were analyzed, including 2,196 (952 male 1,244 female) patients diagnosed with influenza between 1 September 2014 and 31 August 2017. Although only patients with type 1 diabetes were included, adjusted analysis showed that individuals had a 1.3-fold (95% confidence interval: 1.15-1.46) higher risk of developing type 1 diabetes in the first 180 days after influenza diagnosis than that at other times.

CONCLUSIONS

In this Japanese population-based cohort, the risk of new-onset type 1 diabetes may increase after the diagnosis of influenza. These results, which must be confirmed in other populations, suggest that influenza may be a causal factor for new-onset type 1 diabetes. The molecular mechanisms underlying the potential etiological relationship between influenza and type 1 diabetes should be elucidated.

Appropriate definition of diabetes using an administrative database: A cross-sectional cohort validation study

Aims/Introduction

The purpose of the present study was to quantify errors in the diagnosis of diabetes for use in the national database, using a sufficient population size.

Materials and methods

A claims database constructed by the JMDC (Tokyo, Japan), using standardized disease classifications and anonymous record linkage, was used in this validation study. We included patients with health insurance claims data from April 2005 to March 2019 in the JMDC claims database. We excluded patients without a record of specific health checkups in Japan. Sample size calculation was based on a 5% prevalence of diabetes and 0.4% absolute accuracy (i.e., 1,250,000 individuals), to calculate the sensitivity, specificity, positive predictive value and negative predictive value.

Results

In total, 2,999,152 patients were included in this study, of which 165,515 were classified as having diabetes based on specific health checkups (validation cohort prevalence of 5.5%). The newly devised algorithm had three elements – the diagnosis‐related codes for diabetes without suspected flag, the medication codes for diabetes and then these two codes on the same record – and yielded a sensitivity of 74.6%, positive predictive value of 88.4% and Kappa Index of 0.80 (the highest values).

Conclusions

In future claims database studies, our validated algorithms will be useful as diagnostic criteria for diabetes.

Incidence of central serous chorioretinopathy (2011-2018): a nationwide population-based cohort study of Japan

AIMS

The aim of this study was to elucidate the epidemiological background of central serous chorioretinopathy (CSC), including its incidence and treatment pattern.

METHODS

This was a population-based longitudinal cohort study using a nationwide health insurance claims database of the Japan Ministry of Health, Labour and Welfare (MHLW). As Japan employs universal health coverage, the database covers more than 95% of claims issued in Japan. We accessed all data stored in the database with permission from the MHLW. We traced all individuals aged 30 years or older and identified individuals with new onset of CSC between January 2011 and December 2018. CSC cases were categorised by age and sex for each year, and incidence rate was calculated. We also identified major treatments for CSC to elucidate the initial treatment pattern.

RESULTS

During the 8-year period, 247 930 incidences of CSC were identified, among which 75.9% were men. The crude incidence rate (per 100 000 person-years) in the general population aged 30 years or older was 34.0 (95% CI 33.9 to 34.2), in men was 54.2 (95% CI 53.9 to 54.4) and in women was 15.7 (95% CI 15.5 to 15.8). The mean age of onset was lower in men than in women (50.5±12.5 years vs 54.7±13.5 years). Most of the patients with newly diagnosed CSC (86.8%) did not receive major treatment.

CONCLUSIONS

The current study provides the nationwide population-based evidence to clarify the detailed epidemiology of CSC. These results could help to understand the pathogenesis and mechanisms of CSC in the future.

Opioids and the Risk of Fracture: A Self-Controlled Case Series Study in the Clinical Practice Research Datalink

Self-controlled study designs can be used to assess the association between exposures and acute outcomes while controlling for important confounders. Using routinely collected health data, a self-controlled case series design was used to investigate the association between opioid use and bone fractures in 2008–2017 among adults registered in the United Kingdom Clinical Practice Research Datalink. The relative incidence of fracture was estimated, comparing periods when these adults were exposed and unexposed to opioids, adjusted for time-varying confounders. Of 539,369 people prescribed opioids, 67,622 sustained fractures and were included in this study. The risk of fracture was significantly increased when the patient was exposed to opioids, with an adjusted incidence rate ratio of 3.93 (95% confidence interval (CI): 3.82, 4.04). Fracture risk was greatest in the first week of starting opioid use (adjusted incidence rate ratio: 7.81, 95% CI: 7.40, 8.25) and declined with increasing duration of use. Restarting opioid use after a gap in exposure significantly increased fracture risk (adjusted incidence rate ratio: 5.05, 95% CI: 4.83, 5.29) when compared with nonuse. These findings highlight the importance of raising awareness of fractures among patients at opioid initiation and demonstrate the utility of self-controlled methods for pharmacoepidemiologic research.

Hip fracture characteristics and outcomes during COVID-19: a large retrospective national database review

Background

The COVID-19 pandemic has impacted healthcare in various vulnerable patient subpopulations. However, data are lacking on the impact of COVID-19 on hip fractures, seen mainly in older patients. Using national claims data, we aimed to describe the epidemiology during the first COVID-19 wave in the USA.

Methods

We compared patients admitted for hip fractures during March and April of 2020 with those admitted in 2019 in terms of patient and healthcare characteristics, COVID-19 diagnosis, and outcomes. An additional comparison was made between COVID-19-positive and -negative patients. Outcomes included length of hospital stay (LOS), admission to an ICU, ICU LOS, use of mechanical ventilation, 30-day readmission, discharge disposition, and a composite variable of postoperative complications.

Results

Overall, 16 068 hip fractures were observed in 2019 compared with 7498 in 2020. Patients with hip fractures in 2020 (compared with 2019) experienced earlier hospital discharge and were less likely to be admitted to ICU, but more likely to be admitted to home. Amongst 83 patients with hip fractures with concomitant COVID-19 diagnosis, we specifically observed more non-surgical treatments, almost doubled LOS, a more than 10-fold increased mortality rate, and higher complication rates compared with COVID-19-negative patients.

Conclusions

The COVID-19 pandemic significantly impacted not only volume of hip fractures, but also patterns in care and outcomes. These results may inform policymakers in future outbreaks and how this may affect vulnerable patient populations, such as those experiencing a hip fracture.

Prediction Model of Deep Learning for Ambulance Transports in Kesennuma City by Meteorological Data

PURPOSE

With the aging population in Japan, the prediction of ambulance transports is needed to save the limited medical resources. Some meteorological factors were risks of ambulance transports, but it is difficult to predict in a classically statistical way because Japan has 4 seasons. We tried to make prediction models for ambulance transports using the deep learning (DL) framework, Prediction One (Sony Network Communications Inc., Tokyo, Japan), with the meteorological and calendarial variables.

MATERIALS AND METHODS

We retrospectively investigated the daily ambulance transports and meteorological data between 2017 and 2019. First, to confirm their association, we performed classically statistical analysis. Second, to test the DL framework's utility for ambulance transports prediction, we made 3 prediction models for daily ambulance transports (total daily ambulance transports more than 5 or not, cardiopulmonary arrest (CPA), and trauma) using meteorological and calendarial factors and evaluated their accuracies by internal cross-validation.

RESULTS

During the 1095 days of 3 years, the total ambulance transports were 5948, including 240 CPAs and 337 traumas. Cardiogenic CPA accounted for 72.3%, according to the Utstein classification. The relation between ambulance transports and meteorological parameters by polynomial curves were statistically obtained, but their r2s were small. On the other hand, all DL-based prediction models obtained satisfactory accuracies in the internal cross-validation. The areas under the curves obtained from each model were all over 0.947.

CONCLUSION

We could statistically make polynomial curves between the meteorological variables and the number of ambulance transport. We also preliminarily made DL-based prediction models. The DL-based prediction for daily ambulance transports would be used in the future, leading to solving the lack of medical resources in Japan.

Long-term prognosis of enteral feeding and parenteral nutrition in a population aged 75 years and older: a population-based cohort study

Background

Enteral feeding and parenteral nutrition (PN) using gastrostomy (GS) and a nasogastric tube feeding (NGT) and PN should be initiated for older patients based on their prognoses. This study aimed to investigate the long-term prognosis of patients aged ≥75 years who underwent enteral feeding via GS and NGT as well as PN.

Methods

A population-based cohort study was conducted using Japan’s universal health insurance claims in the Nara Prefecture. This study enrolled 3,548 patients aged ≥75 years who received GS (N=770), NGT (N=2,370), and PN (N=408) during hospital admissions between April 2014 and March 2016. The GS group was further categorized into secondary GS (N=400) with preceding NGT or PN within 365 days and primary GS (N=370) without preceding NGT or PN groups. In the secondary GS group, 356 (96%) patients received NGT (versus PN). The outcome was mortality within 730 days after receiving GS, NGT, and PN. Cox regression analyses in cases with or without malignant diseases, adjusted for sex, age, comorbidity, and hospital type, were performed to compare mortality in the groups.

Results

Of the 3,548 participants, 2,384 (67%) died within 730 days after the initiation of GS and NGT and PN. The 2-year mortality rates in the secondary GS, primary GS, NGT, and PN groups were 58%, 66%, 68%, and 83% in patients without malignancies and 67%, 71%, 74%, and 87% in those with malignancies, respectively. In the non-malignant group, Cox regression analysis revealed that secondary GS (hazard ratio (HR) = 0.43, 95% CI: 0.34–0.54), primary GS (HR = 0.51, 95% CI: 0.40–0.64), and NGT (HR = 0.71, 95% CI: 0.58-0.87) were statistically significantly associated with lower mortality compared with PN.

Conclusions

Approximately 58% to 87% patients aged ≥75 years died within 730 days after initiation of nutrition through GS, NGT, or PN. Patients with non-malignant diseases who received secondary GS exhibited better 2-year prognosis than those who received NGT or PN. Healthcare professionals should be aware of the effectiveness and limitations of enteral feeding and PN when considering their initiation.

Effect of Statewide Social Distancing and Stay-At-Home Directives on Orthopaedic Trauma at a Southwestern Level 1 Trauma Center During the COVID-19 Pandemic

OBJECTIVES

To compare orthopaedic trauma volume and mechanism of injury before and during statewide social distancing and stay-at-home directives.

DESIGN

Retrospective.

SETTING

Level 1 trauma center.

PATIENTS/PARTICIPANTS

One thousand one hundred thirteen patients sustaining orthopaedic trauma injuries between March 17 and April 30 of years 2018, 2019, and 2020.

INTERVENTION

Statewide social distancing and stay-at-home directives.

MAIN OUTCOME MEASUREMENTS

Number of consults, mechanism of injury frequency, and type of injury frequency.

RESULTS

During the COVID-19 pandemic, orthopaedic trauma consult number decreased. Injuries due to gunshot wounds increased and those due to automobile versus pedestrian accidents decreased. Time-to-presentation increased and length of stay decreased. Operative consults remained unchanged.

CONCLUSIONS

Orthopaedic trauma injuries continued to occur during the COVID-19 pandemic at an overall decreased rate, however, with a different distribution in mechanism and type of injury.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Incidence and seasonality of type 1 diabetes: a population-based 3-year cohort study using the National Database in Japan

INTRODUCTION

To investigate the incidence of type 1 diabetes by age group (0-19, 20-39, 40-59, ≥60 years) in Japan and whether there is seasonality in this incidence.

RESEARCH DESIGN AND METHODS

The incidence of type 1 diabetes from September 2014 to August 2017 was estimated using 2013-2018 data from the National Database of Health Insurance Claims and Specific Health Check-ups of Japan. The incidence rate was analyzed using Tango's Index and the self-controlled case series method.

RESULTS

Overall, 10 400 of the 79 175 553 included individuals were diagnosed with type 1 diabetes. The incidence of type 1 diabetes from September 2014 to August 2017 was 4.42/100 000 person-years. The incidence rates for men aged 0-19, 20-39, 40-59, and ≥60 years were 3.94, 5.57, 5.70, and 3.48, respectively. Among women, the incidence rates for the same age ranges were 5.22, 4.83, 4.99, and 3.31, respectively. Tango's index showed that the incidence rate of type 1 diabetes was significantly associated with seasons among those aged 0-19 years. Further, the self-controlled case series method showed a significant interaction between age and season, with the incidence of type 1 diabetes being higher in spring for patients younger than 20 years of age.

CONCLUSIONS

In Japan, men aged 40-59 years and women aged 0-19 years are the groups with the highest incidence of type 1 diabetes. Further, the incidence of younger-onset diabetes in Japan was higher in spring (from March to May).

Upper Extremity Fractures in Children-Comparison between Worldwide, Romanian and Western Romanian Region Incidence

(1) Background: Fractures represent a significant part of all pediatric injuries, with distal forearm fracture being the most common fracture type in children. (2) Methods: In this comparative, epidemiological study we collected fracture incidence data from the scientific literature and compared it to real-world data extracted from the Romanian national and regional hospital database. In order to collect information on the epidemiology of upper extremity fractures in children, we conducted a systematic literature review on Medline, via PubMed. Extracted incidence data were stratified by fracture location, age or age interval and gender. Nationwide and Western Region incidence values were calculated for different fracture locations of the upper extremity using data extracted from a centralized hospital database. Incidence values were calculated using the mid-2018 census data. The search was restricted to the pediatric population. (3) Results: Incidence values for upper arm fractures nationwide and for Western Region were 54.83/100,000 person-years and 64.79/100,000 person-years, respectively. Forearm fractures had an incidence of 139.77/100,000 person-years and 139.56/100,000 person-years, respectively. The overall incidence of upper extremity fractures nationwide and for the Romanian Western Region were 206.02/100,000 person-years and 220.14/100,000 person-years, respectively. (4) Conclusions: Incidence of upper extremity fractures in the pediatric population varies according to the analyzed data. The calculated incidence depends on the site of fractures, assessed population (worldwide, Romanian population or regional-Western part of Romania) or patients' age.

Validity of Claims Diagnosis Codes for Cardiovascular Diseases in Diabetes Patients in Japanese Administrative Database

Background

Observational studies using large claims databases for diabetes patients have been increasingly conducted. While validation of outcomes is important in such studies, validation studies from Japan are still scarce and small in scale with questions remaining on the representativeness of their findings. We examined the positive predictive value (PPV) of outcomes that often develop in type 2 diabetes patients: cardiovascular outcomes including congestive heart failure (CHF), myocardial infarction (MI), stroke-related diseases, and renal outcomes including end stage renal disease (ESRD), and death using a large Japanese database containing administrative claims and electronic medical record (EMR) data.

Patients and Methods

We used patient-level administrative claims data from 2003 and EMR data from 1985 to the most recent data up to December 2018 provided by Real World Data Co., Ltd. The database consisted of data from over 200 hospitals including ≥12 million uniquely identifiable patients. Among patients who had ≥1 type 2 diabetes diagnosis in the EMR, those who had administrative claims for each outcome were identified, and then the PPV was calculated for each outcome using the EMR as the gold standard.

Results

The numbers of patients identified for each outcome were 1,700 for MI, 2,027 for hemorrhagic stroke, 3,722 for ESRD, 4,723 for ischemic stroke, 5,404 for CHF, 6,678 for any type of stroke, and 10,815 for death. PPVs ranged from 67.4% for ESRD, 78.7% for MI, 80.3% for death, 85.7% for ischemic stroke, 88.9% for any type of stroke, 89.9% for hemorrhagic stroke, and 95.7% for CHF. A post hoc analysis showed PPV for ESRD as 83.8%.

Conclusion

This large-scale validation study on diagnosis in administrative claims showed reasonable PPVs for the outcomes. We believe that the definitions of outcomes can be considered to be appropriate for future studies using Japanese administrative claims data.

Injury epidemiology of workers by age, sex and industrial classification using the medical claim data of National Health Insurance in South Korea, 2012-2015: a population-based retrospective study

OBJECTIVES

This study aimed to evaluate the risk of inpatient hospitalisation for all-cause injuries, according to age, sex and industrial classification (IC) in South Korea.

DESIGN

A population-based retrospective study.

SETTING AND PARTICIPANTS

Data from the National Health Insurance Database on medical claims for the entire population of South Korean workers aged 25-59 years from January 2012 to December 2015 were retrieved. We observed 30 900 712 person-years (63.1%) in male workers and 18 105 272 person-years (36.9%) in female workers.

MAIN OUTCOME MEASURES

The inpatient hospitalisation for all-cause injury was defined as admission for which the principal diagnosis included S00-T98 in the Korean version of International Classification of Diseases-10 codes.

RESULTS

Of 788 575 hospitalisations for all-cause injuries from 2012 to 2015, there were 565 107 cases in male workers (1 828.8 per 100 000 person-years) and 223 468 cases in female workers (1 234.3 per 100 000 person-years). The top five ICs with hospitalisation rate ratios (HRR) for all-cause injuries in both sexes compared with the financial intermediation IC included agriculture, hunting and forestry (HRR (95% CI); male: 2.09 (1.98 to 2.20); female: 1.53 (1.40 to 1.67)); mining and quarrying (male: 2.05 (1.92 to 2.19); female: 1.54 (1.27 to 1.87)) and fishing (male: 1.68 (1.57 to 1.80); female: 1.71 (1.51 to 1.93)). A U-shaped relationship occurred between age and risk for injuries in males; however, only a linear relationship was shown in females, regardless of IC.

CONCLUSIONS

The risk of injures varied by IC. The workers in agriculture, hunting, forestry, mining, quarrying and fishing were more vulnerable to injuries. The risk for injuries were higher among men and the age effect on this risk differed by sex. Thus, policy makers need to consider specific measures for prevention of injuries according to age, sex and IC.

Data regarding fracture incidence according to fracture site, month, and age group obtained from the large public health insurance claim database in Japan

The National Database of Health Insurance Claims and Specific Health Checkups of Japan includes all health insurance claims submitted in Japan and is considered representative of almost all health claims in Japan. Data regarding fracture incidence, based on the documented diagnoses in the claims and relevant procedure codes, were extracted from the National Database of Health Insurance Claims and Specific Health Checkups of Japan. This data paper includes fracture incidence according to fracture site, month, and age group for the population in Kanto area (Tokyo and surrounding areas), which consists of approximately 42 million people. These data provide supplementary material to be interpreted for the article "Variation in Fracture Risk by Season and Weather: A Comprehensive Analysis across Age and Fracture Site Using a National Database of Health Insurance Claims in Japan" Hayashi et al., and serve as one of the largest epidemiological datasets regarding seasonal differences in fracture incidence according to fracture site and age group.