Purpose: Disease prevalence estimates from population-based administrative databases are often biased due to measurement (misclassification) errors. The purpose of this article is to review the ...methodology for estimating disease prevalence in administrative data, with a focus on bias correction. Source: Several approaches to bias correction in administrative data were reviewed and application of these methods was demonstrated using an example from the literature: physician claims and hospitalization data were employed to estimate diabetes prevalence in Ontario, Canada. Findings: Misclassification bias in prevalence estimates from administrative data can be reduced by developing and selecting an optimal algorithm for case identification, applying a bias correction formula, or using statistical modelling. An algorithm for which sensitivity equals positive predictive value provides an unbiased estimate of prevalence. Bias reduction methods generally require information about the measurement properties of the algorithm, such as sensitivity, specificity, or predictive value. These properties depend on disease type, prevalence, algorithm definition (including the observation window), and may vary by population and time. Prevalence estimates can be improved by applying multivariable disease prediction models. Conclusion: Frequency of a positive case identification algorithm in administrative data is generally not equivalent to disease prevalence. Although prevalence estimates can be corrected for bias using known measurement properties of the algorithm, these properties may be difficult to estimate accurately; therefore, disease prevalence estimates based on administrative data must be treated with caution.
To study the effects of several survey features on response rates in a general population health survey.
In 2012 and 2013, 8000 households in British Columbia, Canada, were randomly allocated to 1 of ...7 survey variants, each containing a different combination of survey features. Features compared included administration modes (paper vs online), prepaid incentive ($2 coin vs none), lottery incentive (instant vs end-of-study), questionnaire length (10 minutes vs 30 minutes), and sampling frame (InfoCanada vs Canada Post).
The overall response rate across the 7 groups was 27.9% (range = 17.1-43.4). All survey features except the sampling frame were associated with statistically significant differences in response rates. The survey mode elicited the largest effect on the odds of response (odds ratio OR = 2.04; 95% confidence interval CI = 1.61, 2.59), whereas the sampling frame showed the least effect (OR = 1.14; 95% CI = 0.98, 1.34). The highest response was achieved by mailing a short paper survey with a prepaid incentive.
In a mailed general population health survey in Canada, a 40% to 50% response rate can be expected. Questionnaire administration mode, survey length, and type of incentive affect response rates.
Abstract
Objectives
To determine whether the introduction of biological DMARDs (bDMARDs) was associated with reduced incidences of total hip and knee arthroplasty (THA/TKA) among patients with RA ...compared with OA.
Methods
Using a population-based cohort in British Columbia, Canada, RA and OA patients diagnosed between 1995 and 2007 were divided into semi-annual cohorts according to diagnosis date. For each cohort, we calculated 8-year incidence rates of THA and TKA. We compared levels and trends of THA/TKA incidence in RA/OA patients diagnosed during pre-bDMARDs (1995–2001) and post-bDMARDs (2003–2007) periods using interrupted time-series analysis, adjusting for baseline characteristics. Adjusted 8-year total joint arthroplasty incidence estimated for RA/OA cohorts diagnosed five years after bDMARDs introduction were compared with expected rates assuming no bDMARDs introduction, based on extrapolation of pre-bDMARDs trends.
Results
We identified 60 227 RA and 288 260 OA incident cases. For cohorts diagnosed pre-bDMARDs, 8-year THA/TKA incidence rates increased over time in both RA and OA. For cohorts diagnosed post-bDMARDs, these rates decreased over time in RA but continued to increase for OA. For RA, differences between the post- and pre-bDMARDs secular trends in incidence rates were −0.49 (P = 0.002) for THA and −0.36 (P = 0.003) for TKA, compared with +0.40 (P = 0.006) and +0.54 (P < 0.001), respectively, for OA. For RA cohorts diagnosed five years after bDMARDs introduction, 8-year incidences were 26.9% and 12.6% lower for THA and TKA, respectively, than expected rates. In contrast, corresponding rates in OA were higher by 11.7% and 16.6%, respectively.
Conclusion
Arthritis onset after bDMARDs introduction is associated with a significant reduction in THA/TKA incidence in RA, but not in OA. The reduction reflects a significant improvement in RA treatment during the biological era.
To review the reliability and validity of the CAGE questionnaire across different patient populations and discuss its role in the detection of alcohol-related problems.
The Cochrane Database for ...Systematic Reviews, Medline, Embase, and Psychinfo were searched. No systematic reviews were found on the Cochrane Database. Search of the other databases yielded one systematic review and one meta-analysis, on different aspects of CAGE. Three articles on reliability and 16 on validity of CAGE were found and used. Studies generally yielded Level II evidence.
CAGE has demonstrated high test-retest reliability (0.80-0.95), and adequate correlations (0.48-0.70) with other screening instruments. The questionnaire is a valid tool for detecting alcohol abuse and dependence in medical and surgical inpatients, ambulatory medical patients, and psychiatric inpatients (average sensitivity 0.71, specificity 0.90). Its performance in primary care patients has been varied, while it has not performed well in white women, prenatal women, and college students. Furthermore, it is not an appropriate screening test for less severe forms of drinking.
CAGE is short, feasible to use, and easily applied in clinical practice. However, users should be aware of its limitations when interpreting the results. A positive screen should be followed by a proper diagnostic evaluation using standard clinical criteria.
To develop a whole-joint, unidimensional, irreversible, and fine-grained MRI knee osteoarthritis (OA) severity score, based on cartilage, osteophytes and meniscus (OA-COM), and to predict progression ...across different severity states using OA-COM as outcome and clinical variables as predictors. Optimal OA-COM thresholds were 12, 18, 24 and 30, for KL grades 1 to 4. Significant predictors of progression (depending on threshold) included physical exam effusion, malalignment and female sex, with other selected predictors age, BMI and crepitus. OA-COM (0-54 range) is a whole-joint, unidimensional, irreversible, and fine-grained MRI OA severity score reflecting cartilage, osteophytes and menisci. OA-COM scores 12, 18, 24 and 30 are equivalent to KL grades 1 to 4, while offering fine-grained differentiation of states between KL grades, and within pre-radiographic disease (KL = 0) or late-stage disease (KL = 4). In modeling, several clinical variables predicted progression across different states over 7 years.
The purpose of this study was to compare three strategies for reducing population health burden of osteoarthritis (OA): improved pharmacological treatment of OA-related pain, improved access to joint ...replacement surgery, and prevention of OA by reducing obesity and overweight.
We applied a validated computer microsimulation model of OA in Canada. The model simulated a Canadian-representative open population aged 20 years and older. Variables in the model included demographics, body mass index, OA diagnosis, OA treatment, mortality, and health-related quality of life. Model parameters were derived from analyses of national surveys, population-based administrative data, a hospital-based cohort study, and the literature. We compared 8 what-if intervention scenarios in terms of disability-adjusted life years (DALYs) relative to base-case, over a wide range of time horizons.
Reductions in DALYs depended on the type of intervention, magnitude of the intervention, and the time horizon. Medical interventions (a targeted increase in the use of painkillers) tended to produce effects quickly and were, therefore, most effective over a short time horizon (a decade). Surgical interventions (increased access to joint replacement) were most effective over a medium time horizon (two decades or longer). Preventive interventions required a substantial change in BMI to generate a significant impact, but produced more reduction in DALYs than treatment strategies over a very long time horizon (several decades).
In this population-based modeling study we assessed the potential impact of three different burden reduction strategies in OA. Data generated by our model may help inform the implementation of strategies to reduce the burden of OA in Canada and elsewhere.
Abstract
Objective
To identify magnetic resonance imaging (MRI) predictors (cartilage C, osteophytes O and meniscus M scores) of prevalent and 3-year incident medial tibiofemoral (MTF) and lateral ...tibiofemoral (LTF) knee joint tenderness and patellofemoral (PF) grind.
Methods
Population-based knee pain cohort aged 40–79 was assessed at baseline (
N
= 255), 3- and 7-year follow-up (
N
= 108 × 2 = 216). COM scores were measured at 6/8/6 subregions respectively. Age-sex-BMI adjusted logistic models predicted prevalence versus relevant COM predictors (medial, lateral or patellar / trochlear groove scores). Fully adjusted models also included all relevant COM predictors. Binary generalized estimating equations models predicting 3-year incidence were also adjusted for individual follow-up time between cycles.
Results
Significant predictors of prevalent MTF tenderness: medial femoral cartilage (fully adjusted odds ratio aOR 1.84; 95% confidence interval CI 1.11, 3.05), female (aOR = 3.05; 1.67, 5.58), BMI (aOR = 1.53 per 5 units BMI; 1.10, 2.11). Predictors of prevalent LTF tenderness: female (aOR = 2.18; 1.22, 3.90). There were no predictors of prevalent PF grind in the fully adjusted model. However, medial patellar osteophytes was predictive in the age-sex-BMI adjusted model. There were no predictors of 3-year incident MTF tenderness. Predictors of 3-year incident LTF tenderness: female (aOR = 3.83; 1.25, 11.77). Predictors of 3-year incident PF grind: lateral patellar osteophytes (aOR = 4.82; 1.69, 13.77). In the age-sex-BMI adjusted model, patellar cartilage was also a predictor.
Conclusion
We explored potential MRI predictors of prevalent and 3-year incident MTF/LTF knee joint tenderness and PF grind. These findings could guide preemptive strategies aimed at reducing these symptoms in the present and future (3-year incidence).
The use of tramadol among osteoarthritis (OA) patients has been increasing rapidly around the world, but population-based studies on its safety profile among OA patients are scarce. We sought to ...determine if tramadol use in OA patients is associated with increased risks of all-cause mortality, cardiovascular diseases (CVD), venous thromboembolism (VTE), and hip fractures compared with commonly prescribed nonsteroidal anti-inflammatory drugs (NSAIDs) or codeine.
Using administrative health datasets from British Columbia, Canada, we conducted a sequential propensity score-matched cohort study among all OA patients between 2005 and 2013. The tramadol cohort (i.e., tramadol initiation) was matched with four comparator cohorts (i.e., initiation of naproxen, diclofenac, cyclooxygenase-2 Cox-2 inhibitors, or codeine). Outcomes are all-cause mortality, first-ever CVD, VTE, and hip fractures within the year after the treatment initiation. Patients were followed until they either experienced an event, left the province, or the 1-year follow-up period ended, whichever occurred first. Cox proportional hazard models were used to estimate hazard ratios after adjusting for competing risk of death.
Overall, 100,358 OA patients were included (mean age: 68 years, 63% females). All-cause mortality was higher for tramadol compared to NSAIDs with rate differences (RDs/1000 person-years, 95% CI) ranging from 3.3 (0.0-6.7) to 8.1 (4.9-11.4) and hazard ratios (HRs, 95% CI) ranging from 1.2 (1.0-1.4) to 1.5 (1.3-1.8). For CVD, no differences were observed between tramadol and NSAIDs. Tramadol had a higher risk of VTE compared to diclofenac, with RD/1000 person-years (95% CI) of 2.2 (0.7-3.7) and HR (95% CI) of 1.7 (1.3-2.2). Tramadol also had a higher risk of hip fractures compared to diclofenac and Cox-2 inhibitors with RDs/1000 person-years (95% CI) of 1.9 (0.4-3.4) and 1.7 (0.2-3.3), respectively, and HRs (95% CI) of 1.6 (1.2-2.0) and 1.4 (1.1-1.9), respectively. No differences were observed between tramadol and NSAIDs for all events.
OA patients initiating tramadol have an increased risk of mortality, VTE, and hip fractures within 1 year compared with commonly prescribed NSAIDs, but not with codeine.
To determine associations between features of osteoarthritis (OA) on MRI and knee pain severity and knee pain progression.
Baseline, 3.3- and 7.5-year assessments were performed for 122 subjects with ...baseline knee pain (age 40-79), sample-weighted for population (with knee pain) representativeness. MRIs were scored for: osteophytes (0:absent to 3:large); cartilage (0:normal to 4:full thickness defect; 0/1 collapsed); subchondral sclerosis (0:none to 3:>50% of site), subchondral cyst (0:absent to 3:severe), bone marrow lesions (0:none to 3:≥50% of site); and meniscus (0:normal to 3:maceration/resection), in 6-8 regions each. Per feature, scores were averaged across regions. Effusion/synovitis (0:absent to 3:severe) was analyzed as ≥2 vs. <2. Linear models predicted WOMAC knee pain severity (0-100), and binary models predicted 10+ (minimum perceptible clinical improvement MPCI) and 20+ (minimum clinically important difference MCID) increases. Models were adjusted for age, sex, BMI (and follow-up time for longitudinal models).
Pain severity was associated with osteophytes (7.17 per unit average; 95% CI = 3.19, 11.15) and subchondral sclerosis (11.03; 0.68, 21.39). MPCI-based pain increase was associated with osteophytes (odds ratio per unit average 3.20; 1.36, 7.55), subchondral sclerosis (5.69; 1.06, 30.44), meniscal damage (1.68; 1.08, 2.61) and effusion/synovitis ≥2 (2.25; 1.07, 4.71). MCID-based pain increase was associated with osteophytes (3.79; 1.41, 10.20) and cartilage defects (2.42; 1.24, 4.74).
Of the features investigated, only osteophytes were consistently associated with pain cross-sectionally and longitudinally in all models. This suggests an important role of bone in early knee osteoarthritis.
To explore the rheumatoid arthritis (RA)-cardiovascular diseases (CVD) association in relative and absolute risk scales among US adults aged ≥20 years over time and the effect modification of the ...association by age.
We analyzed aggregated data from all ten continuous National Health and Nutrition Examination Survey cycles. A sample of 35,062 complete-case subjects was considered. The design-based regressions were used to investigate the associations in relative and absolute scales.
In relative scale, the CVD odds ratio was 2.32, 2.19, and 1.97 among adults with RA than no arthritis in 1999–2006, 2007–2012, and 2013–2018 cycles, respectively. This time trend was not statistically significant. The absolute risk estimates were 11, 10, and 9 per 100 CVD events. We also observed a significant effect modification by age; the higher relative risk among younger adults (<50 years) with RA and higher absolute risk in older adults (≥80 years) with RA were consistent across survey cycles.
There is a significant association between RA and CVD among US adults in both relative and absolute risks. Moreover, age is a significant effect modifier for this association; but with opposing age-related trends in relative and absolute scales.
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