Utilization of routinely collected administrative data in monitoring the incidence of aging dependent hip fracture

Combining Register and Radiological Visits Data Allows to Reliably Identify Incident Wrist Fractures

Purpose

To evaluate how comprehensively wrist fractures can be tracked from the national medical registers, and to propose a method for complementing the register data using time stamps of wrist radiography visits recorded in the radiological image archive.

Patients and Methods

For the Kuopio Osteoporosis Risk Factor and Prevention Study (OSTPRE) cohort of 14220 post-menopausal women, we analysed the data from the Care Register for Health Care, Register for Primary Health Care Visits, self-reports, radiological image archive PACS, and patient records to identify the wrist fractures occurred between 2011 and 2021. Using this gold standard of fractures, we validated the coverage of the registers and image archive and created algorithms to automatically identify fracture events from the registers and/or metadata of wrist radiography visits.

Results

We show that wrist fractures cannot be comprehensively identified based on national registers. To remedy this, our proposed method of combining register and image archive data can lift the coverage from 81% to 94% and reduce false discoveries from 6% to 2%.

Conclusion

The proposed method offers a more reliable way of gathering fracture information. Comprehensive fracture identification is essential in many research settings, such as incidence statistics, prevention studies, and risk assessment models.

Regional and gender-specific analyses give new perspectives for secular trend in hip fracture incidence

In this study, we found that regional disparity in incidence of hip fractures has converged. Also, annual hip fracture risk ratios between genders have systematically diminished over time.

INTRODUCTION

Several studies have reported secular trends in hip fracture incidence, but knowledge about the possible causes is limited. We studied potential explanations by examining spatio-temporal epidemiology of the fractures and estimating relative risks between genders.

METHODS

This observational study was based on all inpatient hospital discharges in 1972-2018 in Finland. We divided the data by gender, 5-year age groups and Finnish sub-regions and estimated gender and age standardized spatio-temporal rates of hip fractures by using a Bayesian age-period-cohort model.

RESULTS

In 1972, women's hip fracture incidence was 1.2-1.3 times higher in western and coastal Finland compared to eastern and inland areas. Also, women had approximately 1.7 times higher average risk to get a hip fracture compared to men. Today, the hip fracture differences between the areas have converged to insignificant and the relative risk between genders has diminished to 1.2. Age-specific relative risks indicate greater hip fracture risk for younger men and older women, and the women's risk increases beyond the risk of men at age 65 which is ten years later than in the beginning of the study period.

CONCLUSION

Incidence of hip fracture has converged significantly between regions and genders. Especially factors related with socioeconomic development and increased frailty and longevity seem to be important. The hip fracture incidence rate ratio between women and men has systematically decreased in time, and more attention should be paid to hip fracture risk in men in the future.

Is Switching from Oral Antidiabetic Therapy to Insulin Associated with an Increased Fracture Risk?

BACKGROUND

Observational studies showed that exposure to exogenous insulin increases fracture risk. However, it remains unclear whether the observed association is a function of the severity of underlying type 2 diabetes mellitus, complications, therapies, comorbidities, or all these factors combined. That being so, and because of the relative infrequency of these events, it is important to study this further in a large-database setting. QUESTION/PURPOSES: (1) Is switching from oral antidiabetic agents to insulin associated with an increased fracture risk? (2) How soon after switching does the increased risk appear, and for how long does this increased risk persist?

METHODS

Data from healthcare utilization databases of the Italian region of Lombardy were used. These healthcare utilization databases report accurate, complete, and interconnectable information of inpatient and outpatient diagnoses, therapies, and services provided to the almost 10 million residents in the region. The 216,624 patients on treatment with oral antidiabetic therapy from 2005 to 2009 were followed until 2010 to identify those who modified their antidiabetic therapy (step 1 cohort). Among the 63% (136,307 patients) who experienced a therapy modification, 21% (28,420 patients) switched to insulin (active exposure), and the remaining 79% (107,887 patients) changed to another oral medication (referent exposure). A 1:1 high-dimension propensity score matching design was adopted for balancing patients on active and referent exposure. Matching failed for 3% of patients (926 patients), so the cohort of interest was formed by 27,494 insulin-referent couples. The latter were followed until 2012 to identify those who experienced hospital admission for fracture (outcome). A Cox proportional hazard model was fitted to estimate the hazard ratio (HR) for the outcome risk associated with active-exposure (first research question). Between-exposure comparison of daily fracture hazard rates from switching until the 24 successive months was explored through the Kernel-smoothed estimator (second research question).

RESULTS

Compared with patients on referent exposure, those who switched to insulin had an increased risk of experiencing any fracture (HR = 1.5 [95% CI 1.3 to 1.6]; p < 0.001). The same risk was observed for hip and vertebral fractures, with HRs of 1.6 (95% CI 1.4 to 1.8; p < 0.001) and 1.8 (95% 1.5 to 2.3; p < 0.001), respectively. Differences in the daily pattern of outcome rates mainly appeared the first 2 months after switching, when the hazard rate of patients on active exposure (9 cases for every 100,000 person-days) was higher than that of patients on referent exposure (4 cases for every 100,000 person-days). These differences persisted during the remaining follow-up, though with reduced intensity.

CONCLUSIONS

We found quantitative evidence that switching from oral antidiabetic therapy to insulin is associated with an increased fracture risk, mainly in the period immediately after the start of insulin therapy. The observed association may result from higher hypoglycemia risk among patients on insulin, which leads to a greater number of falls and resulting fractures. However, although our study was based on a large sample size and highly accurate data, its observational design and the lack of clinical data suggest that future research will need to replicate or refute our findings and address the issue of causality, if any. Until then, though, prescribers and patients should be aware of this risk. Careful control of insulin dosage should be maintained and measures taken to reduce fall risk in these patients.

LEVEL OF EVIDENCE

Level III, therapeutic study.

The Incidence of Hip Fractures in Long-Term Care Homes in Saskatchewan from 2008 to 2012: an Analysis of Provincial Administrative Databases

Background

Hip fractures (HFs) represent an important cause of morbidity and mortality among adults in long-term care (LTC), but lack of detailed epidemiological data poses challenges to intervention planning. We aimed to determine the incidence of HFs among permanent LTC residents in Saskatchewan between 2008 and 2012, using linked, provincial administrative health databases, exploring associations between outcomes and basic individual and institutional characteristics.

Methods

We utilized the Ministry of Health databases to select HF cases based on ICD 10 diagnoses fracture of head and neck of femur, pertrochanteric fracture and subtrochanteric fracture of femur. HF incidence rates in LTC were compared to older adults in the general population.

Results

LTC residents were more likely to be female overall (65.5%), although this varied by age, with only 46.6% female in those under 65, but 77% female among those 90 years and older. Mean age of residents was highest in rural centres (85.2 yrs) and lowest in medium–large centres (81.0 yrs). Of 6,230 cases of HFs in the province during the study period, 2,743 (44%) were in the LTC cohort. Incidence rates per 1,000 person years increased with age and were higher in the LTC group (F = 68.6, M = 49.8) than the overall population (F = 1.62, M = 0.73). Rates of HFs in the province and in LTC were higher in females than males in all age groups, except for the youngest (< 65 years), where males had higher rates, and the oldest category (90+) where rates were similar. Women 90+ years in larger LTC had significantly higher (p = .035) HF rates than those in smaller LTC, and also had significantly (p = .001) higher rates in medium-large compared to smaller population centres. However, after age standardization to the overall SK population, it was apparent that the larger LTC facilities and the medium-large population centres had overall lower HF rates than the small and medium LTC facilities and the small urban and rural PCs, respectively. One health region had particularly high rates, even when accounting for age and sex composition.

Conclusion

Both HF numbers and incidence rates were higher in LTC compared to the overall population, with higher rates in older women, small to medium size LTC, and particular health regions. Our data suggest the need for further exploration of potentially remediable factors for HFs in smaller LTCs, and for targeting specific facilities and regions with outlying HF rates.

Validity of routinely collected data in identifying hip fractures at a major tertiary hospital in Australia

OBJECTIVES

To examine the validity of routinely collected data in identifying hip fractures (HFs) and to identify factors associated with incorrect coding.

METHOD

In a prospective cohort study between January 2014 and June 2016, HFs were identified using physician diagnosis and diagnostic imaging and were recorded in a Registry. Records of HFs in the health information exchange (HIE) were identified using International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification/Australian Classification of Health Interventions/Australian Coding Standards codes. New HFs were estimated by episode of care, hospital admission and with an algorithm. Data from the HIE and the Registry were compared.

RESULTS

The number of HFs as the principal diagnosis (PD) recorded by episode (864) was higher than by admission (743), by algorithm (711) and in the Registry (638). The sensitivity was high for all methods (90-93%) but the positive predictive value was lower for episode (68%) than for admission (80%) or algorithm (81%). The number of HFs with surgery recorded in the PD by episode (639), algorithm (630) and in the Registry (623) was similar but higher than by admission (589). The episode and algorithm methods also had higher sensitivity (91-92%) than the admission method (84%) for HFs with surgery. Factors associated with coding errors included subsequent HF, long hospital stay, intracapsular fracture, younger age, male, HF without surgery and death in hospital.

CONCLUSIONS

When it is not practical to use the algorithm for regular monitoring of HFs, using PD by admission to estimate total HFs and PD by episode in combination with a procedure code to estimate HFs with surgery can produce robust estimations.

A systematic review of intervention thresholds based on FRAX : A report prepared for the National Osteoporosis Guideline Group and the International Osteoporosis Foundation

This systematic review identified assessment guidelines for osteoporosis that incorporate FRAX. The rationale for intervention thresholds is given in a minority of papers. Intervention thresholds (fixed or age-dependent) need to be country-specific.

INTRODUCTION

In most assessment guidelines, treatment for osteoporosis is recommended in individuals with prior fragility fractures, especially fractures at spine and hip. However, for those without prior fractures, the intervention thresholds can be derived using different methods. The aim of this report was to undertake a systematic review of the available information on the use of FRAX® in assessment guidelines, in particular the setting of thresholds and their validation.

METHODS

We identified 120 guidelines or academic papers that incorporated FRAX of which 38 provided no clear statement on how the fracture probabilities derived are to be used in decision-making in clinical practice. The remainder recommended a fixed intervention threshold (n = 58), most commonly as a component of more complex guidance (e.g. bone mineral density (BMD) thresholds) or an age-dependent threshold (n = 22). Two guidelines have adopted both age-dependent and fixed thresholds.

RESULTS

Fixed probability thresholds have ranged from 4 to 20 % for a major fracture and 1.3-5 % for hip fracture. More than one half (39) of the 58 publications identified utilised a threshold probability of 20 % for a major osteoporotic fracture, many of which also mention a hip fracture probability of 3 % as an alternative intervention threshold. In nearly all instances, no rationale is provided other than that this was the threshold used by the National Osteoporosis Foundation of the USA. Where undertaken, fixed probability thresholds have been determined from tests of discrimination (Hong Kong), health economic assessment (USA, Switzerland), to match the prevalence of osteoporosis (China) or to align with pre-existing guidelines or reimbursement criteria (Japan, Poland). Age-dependent intervention thresholds, first developed by the National Osteoporosis Guideline Group (NOGG), are based on the rationale that if a woman with a prior fragility fracture is eligible for treatment, then, at any given age, a man or woman with the same fracture probability but in the absence of a previous fracture (i.e. at the 'fracture threshold') should also be eligible. Under current NOGG guidelines, based on age-dependent probability thresholds, inequalities in access to therapy arise especially at older ages (≥70 years) depending on the presence or absence of a prior fracture. An alternative threshold using a hybrid model reduces this disparity.

CONCLUSION

The use of FRAX (fixed or age-dependent thresholds) as the gateway to assessment identifies individuals at high risk more effectively than the use of BMD. However, the setting of intervention thresholds needs to be country-specific.

Evaluation of the FRAX model for hip fracture predictions in the population-based Kuopio Osteoporosis Risk Factor and Prevention Study (OSTPRE)

Calibration of the Finnish FRAX model was evaluated using a locally derived population-based cohort of postmenopausal women (n = 13,917). Hip fractures were observed from national register-based data and verified from radiological records. For a subpopulation of 11,182 women, there were enough data to calculate the fracture probabilities using the Finnish FRAX tool (without bone mineral density). A 10-year period prevalence of hip fractures to this subpopulation was 0.66 %. The expected numbers of hip fractures were significantly higher than the self reported ones (O/E ratio 0.46; 95 % CI 0.33-0.63), had a tendency to be greater than the observed ones (O/E ratio 0.83; 95 % CI 0.65-1.04), and calibration in terms of goodness-of-fit of absolute probabilities was questionable (P = 0.015). Strikingly, the 10-year period prevalence of hip fractures to the whole cohort was higher (0.84 %) than for the women with FRAX measurements (0.66 %). This was mainly the result of difference between people who had and who had not responded to postal enquiries (0.71 vs. 1.77 %, P < 0.0001). Self-reports missed to capture 38 % of all hip fractures in those who responded and about 45 % of hip fractures in women who had a FRAX estimate. The Finnish FRAX tool seems to provide appropriate discrimination for hip fracture risk, but caution is required in the interpretation of absolute risk, especially if used for population that may not be representing general population per se. Our study also showed that patients with no response had significantly higher hip fracture risk and that the use of purely self-reported hip fractures in calculations results in biased incidence and period prevalence estimates. Such important biases may remain unnoticed if there are no data from other sources available.

Incidence of osteoporotic fractures in elderly women and men in Finland during 2005-2006: a population-based study

BACKGROUND AND AIMS

Osteoporosis is a major health concern in elderly population. Low-trauma fractures offer one way of identifying these patients for treatment. Population-specific incidences of osteoporotic fractures are essential to validate tools for clinical decision making.

MATERIAL AND METHODS

To evaluate population-based osteoporotic fracture incidences in Central Finland, we performed a manual search of low-trauma fractures 2005-2006 from the records of all the local health-care organizations treating trauma patients. We identified low-trauma fracture patients from radiology reports from five health centers serving the inhabitants of nine municipalities and from the patient records of two hospitals in Central Finland. The manually collected data were then compared against data from the Finnish Health Care Register.

RESULTS

The crude incidence of all osteoporotic fractures in 2005-2006 in the population aged 50 years was 1254/100,000 person years: 694/100,000 person years in men and 1718/100,000 person years in women. Fracture numbers derived from register data were similar to those manually collected for hip and humerus fractures, but clearly smaller than those for wrist and ankle fractures.

CONCLUSIONS

Population-based low-trauma fracture incidences, reported here for Finland, constitute a basis for calibration of fracture risk evaluation tools (e.g. the World Health Organization fracture risk evaluation tool, FRAX). This study showed that register data underestimate the incidences of, in particular, distal radius and ankle fractures.

Use of administrative data for national surveillance of osteoporosis and related fractures in Canada: results from a feasibility study

Using administrative data healthcare databases from five Canadian provinces, we compared prevalence estimates of diagnosed osteoporosis and incidence rates for related fractures in Canada. The algorithms adopted showed consistent age and sex patterns across all provinces and will be suitable for national surveillance and monitoring.

PURPOSE

This study aims to evaluate the feasibility of using provincial population-based administrative data to develop a national surveillance system of diagnosed osteoporosis and related fractures (forearm, humerus, vertebra, pelvis, and hip) in Canada.

METHODS

Linked healthcare databases from five provinces representing approximately 85 % of the Canadian population were used. Multiple algorithms combining hospitalizations, physician visits, and osteoporosis prescription drug dispensations were evaluated in each province. The adopted algorithms for diagnosed osteoporosis and incident fractures combined hospitalizations and physician visits based on 3 years and 1 year of data, respectively. Sex-specific age-standardized osteoporosis prevalence and fracture incidence rates were estimated for each province from 1995/1996 to 2007/2008.

RESULTS

Age-standardized prevalence of diagnosed osteoporosis in those ≥50 years increased over the study period but stabilized in the most recent years. Using the adopted algorithm produced provincial estimates ranging from 5.6 to 10.5 % for 2007/2008, with consistent age and sex patterns across provinces. The use of osteoporosis drug data resulted in higher osteoporosis estimates compared with estimates without drug data. Age-standardized incidence of fractures in those ≥40 years showed similar age and sex patterns across all provinces. The highest level of agreement among provinces was for hip and humerus fracture rates, with wider provincial variation for forearm, vertebra, and pelvis fractures.

CONCLUSIONS

Our results are consistent with previous validation works and confirm that the algorithms adopted will be suitable for the national monitoring of diagnosed osteoporosis and related fractures. A similar approach may be applicable to other countries with high-quality administrative data.

Methodological challenges in using the Finnish Hospital Discharge Register for studying fire-related injuries leading to inpatient care

Background

The objective was to examine feasibility of using hospital discharge register data for studying fire-related injuries.

Methods

The Finnish National Hospital Discharge Register (FHDR) was the database used to select relevant hospital discharge data to study usability and data quality issues. Patterns of E-coding were assessed, as well as prominent challenges in defining the incidence of injuries. Additionally, the issue of defining the relevant amount of hospital days accounted for in injury care was considered.

Results

Directly after the introduction of the ICD-10 classification system, in 1996, the completeness of E-coding was found to be poor, but to have improved dramatically around 2000 and thereafter. The scale of the challenges to defining the incidence of injuries was found to be manageable. In counting the relevant hospital days, psychiatric and long-term care were found to be the obvious and possible sources of overestimation.

Conclusions

The FHDR was found to be a feasible data source for studying fire-related injuries so long as potential challenges are acknowledged and taken into account. Hospital discharge data can be a unique and powerful means for injury research as issues of representativeness and coverage of traditional probability samples can frequently be completely avoided.

Trends in hip fracture incidence and mortality in Chinese population from Hong Kong 2001-09

BACKGROUND

there is a suggestion that while the age-adjusted incidence of hip fracture in the West may be declining, the incidence may be rising in Asia.

OBJECTIVE

this study examines the incidence and post-fracture mortality from 2001 to 2009 among the population aged 65 years and over.

METHODS

hip fracture incidence rates and case-fatality rates among Hong Kong population aged 65 and over for the period 2001-09 were obtained from the Hong Kong Hospital Authority (HA) database. Rates were adjusted for age. Poisson and logistic regressions were used to examine trends in incidence and post-fracture mortality, respectively.

RESULTS

the age-adjusted incidence rate of hip fracture among the population aged 65 and over in Hong Kong (per 100,000 population) decreased from 381.6 for men and 853.3 for women in 2001 to 341.7 and 703.1, respectively, in 2009. There were no significant changes in post-fracture mortality trends.

CONCLUSIONS

there is a downward trend in age-specific hip fracture incidence rates since 2001 among Hong Kong Chinese, but no change in post-fracture mortality trends.

Statins and hip fracture prevention--a population based cohort study in women

Objective

To study the association of long-term statin use and the risk of low-energy hip fractures in middle-aged and elderly women.

Design

A register-based cohort study.

Setting

Finland.

Participants

Women aged 45–75 years initiating statin therapy between 1996 and 2001 with adherence to statins ≥80% during the subsequent five years (n = 40 254), a respective cohort initiating hypertension drugs (n = 41 610), and women randomly selected from the population (n = 62 585).

Main Outcome Measures

Incidence rate of and hazard ratio (HR) for low-energy hip fracture during the follow-up extending up to 7 years after the 5-year exposure period.

Results

Altogether 199 low-energy hip fractures occurred during the 135 330 person-years (py) of follow-up in the statin cohort, giving an incidence rate of 1.5 hip fractures per 1000 py. In the hypertension and the population cohorts, the rates were 2.0 per 1000 py (312 fractures per 157 090 py) and 1.0 per 1000 py (212 fractures per 216 329 py), respectively. Adjusting for a propensity score and individual variables strongly predicting the outcome, good adherence to statins for five years was associated with a 29% decreased risk (HR 0.71; 95% CI 0.58–0.86) of a low-energy hip fracture in comparison with adherent use of hypertension drugs. The association was of the same magnitude when comparing the statin users with the population cohort, the HR being 0.69 (0.55–0.87). When women with poor (<40%), moderate (40 to 80%), and good adherence (≥80%) to statins were compared to those with good adherence to hypertension drugs (≥80%) or to the population cohort, the protective effect associated with statin use attenuated with the decreasing level of adherence.

Conclusions

5-year exposure to statins is associated with a reduced risk of low-energy hip fracture in women aged 50–80 years without prior hospitalizations for fractures.

Quality of the Finnish Hospital Discharge Register: a systematic review

AIMS

The Finnish Hospital Discharge Register (FHDR) is one of the oldest individual level hospital discharge registers and has been intensively used for research purposes. The aim of this study was to gather information concerning the quality of FHDR into one place in terms of a systematic review of validation studies that compare data to external information.

METHODS

Several reference databases were searched for validity articles published until January 2012. For each included study, focus of validation, register years examined, number of compared observations, external source(s) of data, summary of validation results, and conclusions concerning the validity of FHDR were extracted.

RESULTS

In total, 32 different studies comparing FHDR data to external information were identified. Most of the studies examined validity in the case of vascular disease, mental disorders or injuries. More than 95% of discharges could be identified from the register. Positive predictive value (PPV) for common diagnoses was between 75 and 99%.

CONCLUSIONS

Completeness and accuracy in the register seem to vary from satisfactory to very good in the register as long as the recognised limitations are taking into account. Poor recording of subsidiary diagnoses and secondary operations and other rarely used items are the most obvious limitations in validity, but do not compromise the value of data in FHDR in being used in studies that are not feasible to conduct otherwise.

Osteoporosis-related fracture case definitions for population-based administrative data

Background

Population-based administrative data have been used to study osteoporosis-related fracture risk factors and outcomes, but there has been limited research about the validity of these data for ascertaining fracture cases. The objectives of this study were to: (a) compare fracture incidence estimates from administrative data with estimates from population-based clinically-validated data, and (b) test for differences in incidence estimates from multiple administrative data case definitions.

Methods

Thirty-five case definitions for incident fractures of the hip, wrist, humerus, and clinical vertebrae were constructed using diagnosis codes in hospital data and diagnosis and service codes in physician billing data from Manitoba, Canada. Clinically-validated fractures were identified from the Canadian Multicentre Osteoporosis Study (CaMos). Generalized linear models were used to test for differences in incidence estimates.

Results

For hip fracture, sex-specific differences were observed in the magnitude of under- and over-ascertainment of administrative data case definitions when compared with CaMos data. The length of the fracture-free period to ascertain incident cases had a variable effect on over-ascertainment across fracture sites, as did the use of imaging, fixation, or repair service codes. Case definitions based on hospital data resulted in under-ascertainment of incident clinical vertebral fractures. There were no significant differences in trend estimates for wrist, humerus, and clinical vertebral case definitions.

Conclusions

The validity of administrative data for estimating fracture incidence depends on the site and features of the case definition.

Optimal strategy to identify incidence of diagnostic of diabetes using administrative data

Background

Accurate estimates of incidence and prevalence of the disease is a vital step toward appropriate interventions for chronic disease like diabetes. A growing body of scientific literature is now available on producing accurate information from administrative data. Advantages of use of administrative data to determine disease incidence include feasibility, accessibility and low cost, but straightforward use of administrative data can produce biased information on incident cases of chronic disease like diabetes. The present study aimed to compare criteria for the selection of diabetes incident cases in a medical administrative database.

Identification of incident injuries in hospital discharge registers

BACKGROUND

Hospital discharge data on injuries constitute a potentially powerful data source for epidemiologic studies. However, reliable identification of incident injury admissions is necessary. The objective of this study was to develop a prediction model for identifying incident hospital admissions, based on variables derived from a hospital discharge register.

METHODS

There were 743,022 hospital admissions for injury in Sweden 1998-2004. Of these, 23,920 were in the county of Uppsala and 24% of these people had previous injury admissions. To determine if these admissions were new injuries or readmissions for earlier injuries, we reviewed 817 randomly selected hospital records. A prediction model for incident injury admissions was developed on the basis of patient age, type of admission (urgent or elective), time interval from the previous injury admission, main diagnosis, and department type.

RESULTS

The final prediction model showed good discrimination (c-statistic = 0.969). This model was applied to the validation dataset using the optimal cut-off level, and the resulting sensitivity and specificity were adjusted according to the proportion with a previous injury admission in each injury category. The injury with the highest proportion of possible readmissions was hip contusion (35%). Nevertheless, using the prediction model, incident hip contusions were identified with a sensitivity of 94% (95% confidence interval = 93%-95%) and a specificity of 95% (94%-97%). The accuracy was higher for all other injury categories.

CONCLUSIONS

Incident injury admissions can be accurately separated from readmissions using a prediction model based on information derived from hospital discharge data.