Patient acceptable symptom state and treatment failure threshold values for work productivity and activity Impairment and EQ-5D-5L in osteoarthritis.

OBJECTIVE: To estimate patient acceptable symptom state (PASS) and treatment failure (TF) threshold values for Work Productivity and Activity Impairment (WPAI) measure and EQ-5D-5L among people with hip or knee osteoarthritis (OA) 3 and 12 months following participation in a digital self-management intervention (Joint Academy®). METHODS: Among the participants, we computed work and activity impairments scores (both 0-100, with a higher value reflecting higher impairment) and the Swedish hypothetical- (range: - 0.314 to 1) and experience-based (range: 0.243-0.976) EQ-5D-5L index scores (a higher score indicates better health status) at 3- (n = 14,607) and 12-month (n = 2707) follow-ups. Threshold values for PASS and TF were calculated using anchor-based adjusted predictive modeling. We also explored the baseline dependency of threshold values according to pain severity at baseline. RESULTS: Around 42.0% and 48.3% of the participants rated their current state as acceptable, while 4.2% and 2.8% considered the treatment had failed at 3 and 12 months, respectively. The 3-month PASS/TF thresholds were 16/29 (work impairment), 26/50 (activity impairment), 0.92/0.77 (hypothetical EQ-5D-5L), and 0.87/0.77 (the experience-based EQ-5D-5L). The thresholds at 12 months were generally comparable to those estimated at 3 months. There were baseline dependencies in PASS/TF thresholds with participants with more severe baseline pain considering poorer (more severe) level of WPAI/EQ-5D-5L as satisfactory. CONCLUSION: PASS and TF threshold values for WPAI and EQ-5D-5L might be useful for meaningful interpretation of these measures among people with OA. The observed baseline dependency of estimated thresholds limits their generalizability and values should be applied with great caution in other settings/populations.

Weekly pain trajectories among people with knee or hip osteoarthritis participating in a digitally delivered first-line exercise and education treatment.

OBJECTIVE: Digital self-management programs are increasingly used in the management of osteoarthritis (OA). Little is known about heterogeneous patterns in response to these programs. We describe weekly pain trajectories of people with knee or hip OA over up to 52-week participation in a digital self-management program. METHODS: Observational cohort study among participants enrolled between January 2019 and September 2021 who participated at least 4 and up to 52 weeks in the program (n = 16 274). We measured pain using Numeric Rating Scale (NRS 0-10) and applied latent class growth analysis to identify classes with similar trajectories. Associations between baseline characteristics and trajectory classes were examined using multinomial logistic regression and dominance analysis. RESULTS: We identified 4 pain trajectory classes: "mild-largely improved" (30%), "low moderate-largely improved" (34%), "upper moderate-improved" (24%), and "severe-persistent" (12%). For classes with decreasing pain, the most pain reduction occurred during first 20 weeks and was stable thereafter. Male sex, older age, lower body mass index (BMI), better physical function, lower activity impairment, less anxiety/depression, higher education, knee OA, no walking difficulties, no wish for surgery and higher physical activity, all measured at enrolment, were associated with greater probabilities of membership in "mild-largely improved" class than other classes. Dominance analysis suggested that activity impairment followed by wish for surgery and walking difficulties were the most important predictors of trajectory class membership. CONCLUSIONS: Our results highlight the importance of reaching people with OA for first-line treatment prior to developing severe pain, poor health status and a wish for surgery.

Digital self-management, analgesic use and patient-reported outcomes in knee or hip osteoarthritis.

OBJECTIVE: To investigate changes in analgesic use before and after participation in a digital first-line treatment program (exercise and patient education) in persons with knee or hip OA and to explore associations between these changes in medication use and participant-reported pain and function. DESIGN: Retrospective cohort study with pre-post measures. SETTING: Community setting, Sweden. PARTICIPANTS: Individuals (n=4100, mean [SD] age 64.5 [9.3], 73.3% females) participating in the digital program. INTERVENTIONS: A digital supervised education and exercise therapy. MAIN OUTCOME MEASURES: Self-reported analgesic use for knee/hip pain during the past month at baseline and 12-week follow-up, knee/hip NRS pain (0-10, a higher value indicating more pain), and KOOS-12 or HOOS-12 Function subscale (0-100, higher values indicating better function). McNemar test, multivariable logistic regression and linear random intercept model were used for statistical analyses. RESULTS: Among participants, 61.4% and 49.4% were analgesic users at baseline and 12-week follow up, respectively, (absolute reduction 12.0%, 95%CI 10.5, 13.5). Being female, having hip OA, lower education, higher body mass index, living outside large metropolitan cities, co-existing rheumatoid arthritis, and walking difficulties were associated with higher odds of analgesic use at baseline. At both time points, persons not using analgesics at the time reported better outcomes. All groups but "new users" experienced improvements in their pain and function following participation in digital program with the greatest improvements observed among "quitters". CONCLUSION: Engaging in a digital exercise and patient education program as a primary treatment for knee or hip osteoarthritis was associated with a reduction in the use of analgesics. The greatest improvements were seen for those who stopped analgesic use. These results highlight the importance of providing effective first-line treatment to people with knee or hip OA.

Income-Related Inequality Changes in Osteoarthritis First-Line Interventions: A Cohort Study.

OBJECTIVE: To examine income-related inequality changes in the outcomes of an osteoarthritis (OA) first-line intervention. DESIGN: Retrospective cohort study. SETTING: Swedish health care system. PARTICIPANTS: We included 115,403 people (age: 66.2±9.7 years; females 67.8%; N=115,403) with knee (67.8%) or hip OA (32.4%) recorded in the "Swedish Osteoarthritis Registry" (SOAR). INTERVENTIONS: Exercise and education. MAIN OUTCOME MEASURES: Erreygers' concentration index (E) measured income-related inequalities in "Pain intensity," "Self-efficacy," "Use of NSAIDs," and "Desire for surgery" at baseline, 3-month, and 12-month follow-ups and their differences over time. E-values range from -1 to +1 if the health variables are more concentrated among people with lower or higher income. Zero represents perfect equality. We used entropy balancing to address demographic and outcome imbalances and bootstrap replications to estimate confidence intervals for E differences over time. RESULTS: Comparing baseline to 3 months, "pain" concentrated more among individuals with lower income initially (E=-0.027), intensifying at 3 months (difference with baseline: E=-0.011 [95% CI: -0.014; -0.008]). Similarly, the "Desire for surgery" concentrated more among individuals with lower income initially (E=-0.009), intensifying at 3 months (difference with baseline: E=-0.012 [-0.018; -0.005]). Conversely, "Self-efficacy" concentrated more among individuals with higher income initially (E=0.058), intensifying at 3 months (difference with baseline: E=0.008 [0.004; 0.012]). Lastly, the "Use of NSAIDs" concentrated more among individuals with higher income initially (E=0.068) but narrowed at 3 months (difference with baseline: E=-0.029 [-0.038; -0.021]). Comparing baseline with 12 months, "pain" concentrated more among individuals with lower income initially (E=-0.024), intensifying at 12 months (difference with baseline: E=-0.017 [-0.022; -0.012]). Similarly, the "Desire for surgery" concentrated more among individuals with lower income initially (E=-0.016), intensifying at 12 months (difference with baseline: E=-0.012 [-0.022; -0.002]). Conversely, "Self-efficacy" concentrated more among individuals with higher income initially (E=0.059), intensifying at 12 months (difference with baseline: E=0.016 [0.011; 0.021]). The variable 'Use of NSAIDs' was not recorded in the SOAR at 12-month follow-up. CONCLUSION: Our results highlight the increase of income-related inequalities in the SOAR over time.

Arthroscopic Partial Meniscectomy for a Degenerative Meniscus Tear Is Not Cost Effective Compared With Placebo Surgery: An Economic Evaluation Based on the FIDELITY Trial Data.

BACKGROUND: In patients with a degenerative tear of the medial meniscus, recent meta-analyses and systematic reviews have shown no treatment benefit of arthroscopic partial meniscectomy (APM) over conservative treatment or placebo surgery. Yet, advocates of APM still argue that APM is cost effective. Giving advocates of APM their due, we note that there is evidence from the treatment of other musculoskeletal complaints to suggest that a treatment may prove cost effective even in the absence of improvements in efficacy outcomes, as it may lead to other benefits, such as diminished productivity loss and reduced costs, and so the question of cost effectiveness needs to be answered for APM. QUESTIONS/PURPOSES: (1) Does APM result in lower postoperative costs compared with placebo surgery? (2) Is APM cost-effective compared with placebo surgery? METHODS: One hundred forty-six adults aged 35 to 65 years with knee symptoms consistent with a degenerative medial meniscus tear and no knee osteoarthritis according to the American College of Rheumatology clinical criteria were randomized to APM (n = 70) or placebo surgery (n = 76). In the APM and placebo surgery groups, mean age was 52 ± 7 years and 52 ± 7 years, and 60% (42 of 70) and 62% (47 of 76) of participants were men, respectively. There were no between-group differences in baseline characteristics. In both groups, a standard diagnostic arthroscopy was first performed. Thereafter, in the APM group, the torn meniscus was trimmed to solid meniscus tissue, whereas in the placebo surgery group, APM was carefully mimicked but no resection of meniscal tissue was performed; as such, surgical costs were the same in both arms and were not included in the analyses. All patients received identical postoperative care including a graduated home-based exercise program. At the 2-year follow-up, two patients were lost to follow-up, both in the placebo surgery group. Cost effectiveness over the 2-year trial period was computed as incremental net monetary benefit (INMB) for improvements in quality-adjusted life years (QALY), using both the societal (primary) and healthcare system (secondary) perspectives. To be able to consider APM cost effective, the CEA analysis should yield a positive INMB value. Nonparametric bootstrapping was used to assess uncertainty. Several one-way sensitivity analyses were also performed. RESULTS: APM did not deliver lower postoperative costs, nor did it convincingly improve quality of life scores when compared with placebo surgery. From a societal perspective, APM was associated with € 971 (95% CI -2013 to 4017) higher costs and 0.015 (95% CI -0.011 to 0.041) improved QALYs over 2-year follow-up compared with placebo surgery. Both differences were statistically inconclusive (a wide 95% CI that crossed the line of no difference). Using the conventional willingness to pay (WTP) threshold of € 35,000 per QALY, APM resulted in a negative INMB of € -460 (95% CI -3757 to 2698). In our analysis, APM would result in a positive INMB only when the WTP threshold rises to about € 65,000 per QALY. The wide 95% CIs suggests uncertain cost effectiveness irrespective of chosen WTP threshold. CONCLUSION: The results of this study lend further support to clinical practice guidelines recommending against the use of APM in patients with a degenerative meniscus tear. Given the robustness of existing evidence demonstrating no benefit or cost effectiveness of APM over nonsurgical treatment or placebo surgery, future research is unlikely to alter this conclusion.Level of Evidence Level III, economic analysis.

Within-person change in patient-reported outcomes and their association with the wish to undergo joint surgery during a digital first-line intervention for osteoarthritis.

AIM: To study the association between within-person changes in patient-reported outcomes (PROMs) and wish for joint surgery during participation in a digital first-line intervention comprising exercise and education for knee/hip osteoarthritis (OA). METHODS: Retrospective observational registry study. Participants enrolled between June 1, 2018 and October 30, 2021, with follow-up data at three months (n = 13,961). We used asymmetric fixed effect (conditional) logistic regressions to study the association between change in wish to undergo surgery at last available time point (3, 6, 9, or 12 months) and improvement or worsening of PROMs pain (0-10), quality of life (QoL) (EQ5D-5L, 0.243-0.976), overall health (0-10), activity impairment (0-10), walking difficulties (yes/no), fear of movement (yes/no), and Knee/Hip injury and Osteoarthritis Outcome Score 12 Items (KOOS-12/HOOS-12, 0-100) function and QoL subscales. RESULTS: The proportion of participants wishing to undergo surgery declined by 2% (95% CI: 1.9, 3.0), from 15.7% at the baseline to 13.3% at 3 months. Generally, improvements in PROMs were associated with reduced likelihood of wishing for surgery, while worsening was associated with increased likelihood. For pain, activity impairment EQ-5D and KOOS/HOOS QoL, a worsening led to a change in the probability of wish for surgery of larger absolute magnitude than an improvement in the same PROM. CONCLUSIONS: Within-person improvements in PROMs are associated with reduced wish for surgery while worsenings with an increased wish for surgery. Larger improvements in PROMs may be needed to match the magnitude of the change in wish for surgery associated with a worsening in the same PROM.

Digital self-management of hip and knee osteoarthritis and trajectories of work and activity impairments.

OBJECTIVE: To investigate the trajectories of work and activity impairments among people participating in a digital self-management program for osteoarthritis (OA). METHODS: We conducted an observational longitudinal study using data for baseline, 3, 6, 9 and 12 months follow ups from people participating in a digital OA treatment between June 2018 and September 2021. The Work Productivity and Activity Impairment-Osteoarthritis (WPAI-OA) questionnaire was used to measure work and activity impairments. We applied linear mixed models and group-based trajectory modelling (GBTM) to assess the trajectories of work and activity impairments and their variability. Dominance analysis was performed to explore the relative importance of baseline characteristics in predicting the trajectory subgroup membership. RESULTS: A total of 14,676 participants with mean (± standard deviation) age 64.0 (± 9.1) years and 75.5% females were included. The adjusted mean improvements in work impairment from baseline were 5.8% (95% CI 5.3, 6.4) to 6.1% (95% CI 5.5, 6.8). The corresponding figures for activity impairment were 9.4% (95% CI 9.0, 9.7) to 11.3% (95% CI 10.8, 11.8). GBTM identified five (low baseline-declining, moderate baseline-declining, high baseline-declining, very high baseline-substantially declining, and very high baseline-persistent) and three (low baseline-declining, mild baseline-declining, high baseline-declining) subgroups with distinct trajectories of activity and work impairments. Dominance analysis showed that baseline pain was the most important predictor of membership in trajectory subgroups. CONCLUSION: While participation in a digital self-management program for OA was, on average, associated with improvements in work and activity impairments, there were substantial variations among the participants. Baseline pain may provide useful insights to predict trajectories of work and activity impairments.

Does lower educational attainment increase the risk of osteoarthritis surgery? a Swedish twin study.

BACKGROUND: Previous studies have reported an inverse association between educational attainment and different osteoarthritis (OA) outcomes. However, none of the previous studies have accounted for potential confounding by early-life environment and genetics. Thus, we aimed to examine the association between educational attainment and knee and hip OA surgery using twin data. METHODS: From the Swedish Twin Registry (STR), we identified dizygotic (DZ) and monozygotic (MZ) twins. All twins in the STR aged 35 to 64 years were followed from January the 1st 1987 or the date they turned 35 years until OA surgery, relocation outside Sweden, death or the end of 2016 (18,784 DZ and 8,657 MZ complete twin pairs). Associations between educational attainment and knee and hip OA surgery were estimated in models matched on twin pairs, using Weibull within-between (WB) shared frailty model. RESULTS: For knee OA surgery, the analysis matched on MZ twins yielded a within-estimate hazard ratio (HR) per 3 years of education, of 1.06 (95% CI: 0.81, 1.32), suggesting no association between the outcome and the individual´s education. Rather, there seemed to be a so called familial effect of education, with a between-pair estimate of HR = 0.71 (95% CI: 0.41, 1.01). For hip OA surgery, the within- and between-pair estimates for MZ twins were 0.92 (95% CI: 0.69, 1.14) and 1.15 (95% CI: 0.87, 1.42), respectively. CONCLUSIONS: Our results suggest that the inverse associations between education and knee/hip OA surgery observed in cohort studies are potentially confounded by unobserved familial factors like genetics and/or early life exposures.

The gap in life expectancy and lifespan inequality between Iran and neighbour countries: the contributions of avoidable causes of death.

BACKGROUND: Healthcare system and intersectoral public health policies play a crucial role in improving population health and reducing health inequalities. This study aimed to quantify their impact, operationalized as avoidable deaths, on the gap in life expectancy (LE) and lifespan inequality (LI) between Iran and three neighbour countries viz., Turkey, Qatar, and Kuwait in 2015-2016. METHODS: Annual data on population and causes of deaths by age and sex for Iran and three neighbour countries were obtained from the World Health Organization mortality database for the period 2015-2016. A recently developed list by the OECD/Eurostat was used to identify avoidable causes of death (with an upper age limit of 75). The cross-country gaps in LE and LI (measured by standard deviation) were decomposed by age and cause of death using a continuous-change model. RESULTS: Iranian males and females had the second lowest and lowest LE, respectively, compared with their counterparts in the neighbour countries. On the other hand, the highest LIs in both sexes (by 2.3 to 4.5 years in males and 1.1 to 3.3 years in females) were observed in Iran. Avoidable causes contributed substantially to the LE and LI gap in both sexes with injuries and maternal/infant mortality represented the greatest contributions to the disadvantages in Iranian males and females, respectively. CONCLUSIONS: Higher mortality rates in young Iranians led to a double burden of inequality -shorter LE and greater uncertainty at timing of death. Strengthening intersectoral public health policies and healthcare quality targeted at averting premature deaths, especially from injuries among younger people, can mitigate this double burden.

Osteoarthritis and risk of hospitalization for ambulatory care-sensitive conditions: a general population-based cohort study.

OBJECTIVE: To determine the association between OA and risk of hospitalization for ambulatory care-sensitive conditions (HACSCs). METHODS: We included all individuals aged 40-85 years who resided in Skåne, Sweden on 31 December 2005 with at least one healthcare consultation during 1998-2005 (n = 515 256). We identified those with a main diagnosis of OA between 1 January 1998 and 31 December 2016. People were followed from 1 January 2006 until an HACSC, death, relocation outside Skåne, or 31 December 2016 (whichever occurred first). OA status was treated as a time-varying covariate (those diagnosed before 1 January 2006 considered as exposed for whole study period). We assessed relative [hazard ratios (HRs) using Cox proportional hazard model] and absolute (hazard difference using additive hazard model) effects of OA on HACSCs adjusted for potential confounders. RESULTS: Crude incidence rates of HACSCs were 239 (95% CI: 235, 242) and 151 (150, 152) per 10 000 person-years among OA and non-OA persons, respectively. The OA persons had an increased risk of HACSCs [HR (95% CI) 1.11 (1.09, 1.13)] and its subcategories of medical conditions except chronic obstructive pulmonary disease [HR (95% CI) 0.86 (0.81, 0.90)]. There were 20 (95% CI: 16, 24) more HACSCs per 10 000 person-years in OA compared with non-OA persons. While HRs for knee and hip OA were generally comparable, only knee OA was associated with increased risk of hospitalization for diabetes. CONCLUSION: OA is associated with an increased risk of HACSCs, highlighting the urgent need to improve outpatient care for OA patients.

The contributions of public health policies and healthcare quality to gender gap and country differences in life expectancy in the UK.

BACKGROUND: In many high-income countries, life expectancy (LE) has increased, with women outliving men. This gender gap in LE (GGLE) has been explained with biological factors, healthy behaviours, health status, and sociodemographic characteristics, but little attention has been paid to the role of public health policies that include/affect these factors. This study aimed to assess the contributions of avoidable causes of death, as a measure of public health policies and healthcare quality impacts, to the GGLE and its temporal changes in the UK. We also estimated the contributions of avoidable causes of death into the gap in LE between countries in the UK. METHODS: We obtained annual data on underlying causes of death by age and sex from the World Health Organization mortality database for the periods 2001-2003 and 2014-2016. We calculated LE at birth using abridged life tables. We applied Arriaga's decomposition method to compute the age- and cause-specific contributions into the GGLE in each period and its changes between two periods as well as the cross-country gap in LE in the 2014-2016 period. RESULTS: Avoidable causes had greater contributions than non-avoidable causes to the GGLE in both periods (62% in 2001-2003 and 54% in 2014-2016) in the UK. Among avoidable causes, ischaemic heart disease (IHD) followed by injuries had the greatest contributions to the GGLE in both periods. On average, the GGLE across the UK narrowed by about 1.0 year between 2001-2003 and 2014-2016 and three avoidable causes of IHD, lung cancer, and injuries accounted for about 0.8 years of this reduction. England & Wales had the greatest LE for both sexes in 2014-2016. Among avoidable causes, injuries in men and lung cancer in women had the largest contributions to the LE advantage in England & Wales compared to Northern Ireland, while drug-related deaths compared to Scotland in both sexes. CONCLUSION: With avoidable causes, particularly preventable deaths, substantially contributing to the gender and cross-country gaps in LE, our results suggest the need for behavioural changes by implementing targeted public health programmes, particularly targeting younger men from Scotland and Northern Ireland.

Avoidable deaths in Sweden, 1997-2018: temporal trend and the contribution to the gender gap in life expectancy.

BACKGROUND: Avoidable mortality is considered as a potential indicator of the influences of public health policies and healthcare quality on population health. This study aimed to examine the trend in avoidable mortality and its influence on rising life expectancy (LE) and declining gender gap in LE (GGLE) in Sweden. METHODS: We extracted data on causes of death by age, sex, and year from national registry from 1997 to 2018. The UK Office for National Statistics definition was used to divide causes of death into five mutually exclusive categories: amenable, preventable, amenable & preventable, ischemic heart disease (IHD), and non-avoidable causes. We applied Joinpoint regression to analyse temporal trends in age-standardized mortality rates. The Arriaga method was applied to decompose changes in LE and GGLE by age group and causes of death. RESULTS: Average annual reductions in avoidable vs. non-avoidable mortality were 2.6% (95% CI:2.5, 2.7) vs. 1.4% (95% CI:1.3, 1.5) in men, and 1.6% (95% CI:1.4, 1.9) vs. 0.9% (95% CI:0.7, 1.0) in women over the study period. LE in men rose by 4.1 years between 1997 and 2018 (from 72.8 to 76.9 years), of which 2.4 years (59.3%) were attributable to reductions in avoidable mortality. Corresponding LE gain was 2.3 years in women (from 78.0 in 1997 to 80.3 in 2018) and avoidable mortality accounted for 1.0 year (45.6%) of this gain. Between 1997 and 2018, the GGLE narrowed by 1.9 years, of which 1.4 years (77.7%) were attributable to avoidable causes. Among avoidable causes, while preventable causes had the largest contribution to the GGLE, IHD had the greatest contributions to LE gains and the narrowing GGLE. CONCLUSIONS: Our findings showed that avoidable causes had a substantial contribution to gain in LE with more profound gain in men than in women, resulting in narrowing the GGLE. Lower pace of reductions in preventable than amenable mortality highlights the need for improving the effectiveness of inter-sectoral health policies aimed at behavioural changes.

Probabilistic Quantification of Bias to Combine the Strengths of Population-Based Register Data and Clinical Cohorts-Studying Mortality in Osteoarthritis.

We propose combining population-based register data with a nested clinical cohort to correct misclassification and unmeasured confounding through probabilistic quantification of bias. We have illustrated this approach by estimating the association between knee osteoarthritis and mortality. We used the Swedish Population Register to include all persons resident in the Skåne region in 2008 and assessed whether they had osteoarthritis using data from the Skåne Healthcare Register. We studied mortality through year 2017 by estimating hazard ratios. We used data from the Malmö Osteoarthritis Study (MOA), a small cohort study from Skåne, to derive bias parameters for probabilistic quantification of bias, to correct the hazard ratio estimate for differential misclassification of the knee osteoarthritis diagnosis and confounding from unmeasured obesity. We included 292,000 persons in the Skåne population and 1,419 from the MOA study. The adjusted association of knee osteoarthritis with all-cause mortality in the MOA sample had a hazard ratio of 1.10 (95% confidence interval (CI): 0.80, 1.52) and was thus inconclusive. The naive association in the Skåne population had a hazard ratio of 0.95 (95% CI: 0.93, 0.98), while the bias-corrected estimate was 1.02 (95% CI: 0.59, 1.52), suggesting high uncertainty in bias correction. Combining population-based register data with clinical cohorts provides more information than using either data source separately.

Mapping EQ-5D-3L from the Knee Injury and Osteoarthritis Outcome Score (KOOS).

PURPOSE: To develop a mapping model to estimate EQ-5D-3L from the Knee Injury and Osteoarthritis Outcome Score (KOOS). METHODS: The responses to EQ-5D-3L and KOOS questionnaires (n = 40,459 observations) were obtained from the Swedish National anterior cruciate ligament (ACL) Register for patients ≥ 18 years with the knee ACL injury. We used linear regression (LR) and beta-mixture (BM) for direct mapping and the generalized ordered probit model for response mapping (RM). We compared the distribution of the original data to the distributions of the data generated using the estimated models. RESULTS: Models with individual KOOS subscales performed better than those with the average of KOOS subscale scores (KOOS5, KOOS4). LR had the poorest performance overall and across the range of disease severity particularly at the extremes of the distribution of severity. Compared with the RM, the BM performed better across the entire range of disease severity except the most severe range (KOOS5 < 25). Moving from the most to the least disease severity was associated with 0.785 gain in the observed EQ-5D-3L. The corresponding value was 0.743, 0.772 and 0.782 for LR, BM and RM, respectively. LR generated simulated EQ-5D-3L values outside the feasible range. The distribution of simulated data generated from the BM model was almost identical to the original data. CONCLUSIONS: We developed mapping models to estimate EQ-5D-3L from KOOS facilitating application of KOOS in cost-utility analyses. The BM showed superior performance for estimating EQ-5D-3L from KOOS. Further validation of the estimated models in different independent samples is warranted.

Educational inequalities in all-cause and cause-specific mortality among people with gout: a register-based matched cohort study in southern Sweden.

BACKGROUND: Gout is the most common inflammatory arthritis with a rising prevalence around the globe. While educational inequalities in incidence and prevalence of gout have been reported, no previous study investigated educational inequality in mortality among people with gout. The aim of this study was to assess absolute and relative educational inequalities in all-cause and cause-specific mortality among people with gout in comparison with an age- and sex-matched cohort free of gout in southern Sweden. METHODS: We identified all residents aged ≥30 years of Skåne region with doctor-diagnosed gout (ICD-10 code M10, n = 24,877) during 1998-2013 and up to 4 randomly selected age- and sex-matched comparators free of gout (reference cohort, n = 99,504). These were followed until death, emigration, or end of 2014. We used additive hazards models and Cox regression adjusted for age, sex, marital status, and country of birth to estimate slope and relative indices of inequality (SII/RII). Three cause-of-death attribution approaches were considered for RII estimation: "underlying cause", "any mention", and "weighted multiple-cause". RESULTS: Gout patients with the lowest education had 1547 (95% CI: 1001, 2092) more deaths per 100,000 person-years compared with those with the highest education. These absolute inequalities were larger than in the reference population (1255, 95% CI: 1038, 1472). While the contribution of cardiovascular (cancer) mortality to these absolute inequalities was greater (smaller) in men with gout than those without, the opposite was seen among women. Relative inequality in all-cause mortality was smaller in gout (RII 1.29 [1.18, 1.41]) than in the reference population (1.46 [1.38, 1.53]). The weighted multiple-cause approach generally led to larger RIIs than the underlying cause approach. CONCLUSIONS: Our register-based matched cohort study showed that low level of education was associated with increased mortality among gout patients. Although the magnitude of relative inequality was smaller in people with gout compared with those without, the absolute inequalities were greater reflecting a major mortality burden among those with lower education.

Impact of a national guideline on use of knee arthroscopy: An interrupted time-series analysis.

OBJECTIVE: To assess the impact of the Swedish health authority recommendation against the use of knee arthroscopy in patients aged ≥40 years with knee osteoarthritis (OA). DESIGN: Interrupted time series analysis. SETTING: Public health care in Skåne region. PARTICIPANTS: Patients aged ≥40 years who underwent knee arthroscopy from January 2010 to December 2015. INTERVENTION(S): National guideline's recommendation against the use of knee arthroscopy in patients with knee OA. MAIN OUTCOME MEASURE(S): 1) proportion of patients aged ≥40 years with a main diagnosis of Knee OA and/or degenerative meniscal lesions (DML) who underwent knee arthroscopy, and 2) overall knee arthroscopy rate per 100,000 Skåne population aged ≥40 years. RESULTS: A total of 6,155 knee arthroscopy were performed among people aged ≥40 years during study period. Of 42,044 patients with Knee OA/DML, 3,728 had knee arthroscopy. The recommendation was associated with reductions in the use of knee arthroscopy and two years after the recommendation, there was a reduction of 28.6% (95% CI: 9.3, 47.8) and 34.7% (23.9, 45.4) in proportion of Knee OA/DML patients with knee arthroscopy and the overall knee arthroscopy rate, respectively, relative to that expected if pre-recommendation trend continued. Our sensitivity analysis showed that the use of total knee replacement was stable over the study period. CONCLUSION: The national recommendation was associated with reduction in use of knee arthroscopy in public health care in southern Sweden. However, still 4.5% of these patients underwent knee arthroscopy in 2015 implying that more efforts are required to achieve the recommended target.

The contributions of avoidable causes of death to gender gap in life expectancy and life disparity in the US and Canada: 2001-2019.

OBJECTIVES: This study measures public health policies' and healthcare system's influence, by assessing the contributions of avoidable deaths, on the gender gaps in life expectancy and disparity (GGLD and GGLD, respectively) in the United States (US) and Canada from 2001 to 2019. METHODS: To estimate the GGLE and GGLD, we retrieved age- and sex-specific causes of death from the World Health Organization's mortality database. By employing the continuous-change model, we decomposed the GGLE and GGLD by age and cause of death for each year and over time using females as the reference group. RESULTS: In Canada and the US, the GGLE (GGLD) narrowed (increased) by 0.9 (0.2) and 0.2 (0.3) years, respectively. Largest contributor to the GGLE was non-avoidable deaths in Canada and preventable deaths in the US. Preventable deaths had the largest contributions to the GGLD in both countries. Ischemic heart disease contributed to the narrowing GGLE/GGLD in both countries. Conversely, treatable causes of death increased the GGLE/GGLD in both countries. In Canada, "treatable & preventable" as well as preventable causes of death narrowed the GGLE while opposite was seen in the US. While lung cancer contributed to the narrowing GGLE/GGLD, drug-related death contributed to the widening GGLE/GGLD in both countries. Injury-related deaths contributed to the narrowing GGLE/GGLD in Canada but not in the US. The contributions of avoidable causes of death to the GGLE declined in the age groups 55-74 in Canada and 70-74 in the US, whereas the GGLE widened for ages 25-34 in the US. CONCLUSION: Canada experienced larger reduction in the GGLE compared to the US attributed mainly to preventable causes of death. To narrow the GGLE and GGLD, the US needs to address injury deaths. Urgent interventions are required for drug-related death in both countries, particularly among males aged 15-44 years.

Inflammatory rheumatic diseases and the risk of drug use disorders: a register-based cohort study in Sweden.

To investigate the association between chronic inflammatory rheumatic diseases (CIRD) and drug use disorder (DUD). Individuals aged ≥ 30 years in 2009 that met the following conditions were included: residing in the Skåne region, Sweden, with at least one healthcare contact in person and no history of DUD (ICD-10 codes F11-F16, F18-F19) during 1998-2009 (N = 649,891). CIRD was defined as the presence of rheumatoid arthritis (RA), ankylosing spondylitis (AS), psoriatic arthritis (PsA), or systemic lupus erythematosus. Treating CIRD as a time-varying exposure, we followed people from January 1, 2010 until a diagnosis of DUD, death, relocation outside the region, or December 31, 2019, whichever occurred first. We used flexible parametric survival models adjusted for attained age, sociodemographic characteristics, and coexisting conditions for data analysis. There were 64 (95% CI 62-66) and 104 (88-123) incident DUD per 100,000 person-years among those without and with CIRD, respectively. CIRD was associated with an increased risk of DUD in age-adjusted analysis (hazard ratio [HR] 1.77, 95% CI 1.49-2.09). Almost identical HR (1.71, 95% CI 1.45-2.03) was estimated after adjustment for sociodemographic characteristics, and it slightly attenuated when coexisting conditions were additionally accounted for (1.47, 95% CI 1.24-1.74). Fully adjusted HRs were 1.49 (1.21-1.85) for RA, 2.00 (1.38-2.90) for AS, and 1.58 (1.16-2.16) for PsA. More stringent definitions of CIRD didn't alter our findings. CIRD was associated with an increased risk of DUD independent of sociodemographic factors and coexisting conditions. Key Points • A register-based cohort study including 649,891 individuals aged≥30 residing in the Skåne region, Sweden, was conducted. • Chronic inflammatory rheumatic diseases were associated with higher risks of drug use disorder independent of sociodemographic factors and coexisting conditions.

Twenty-year trajectories of morbidity in individuals with and without osteoarthritis.

OBJECTIVES: To identify multimorbidity trajectories over 20 years among incident osteoarthritis (OA) individuals and OA-free matched references. METHODS: Cohort study using prospectively collected healthcare data from the Skåne region, Sweden (~1.4 million residents). We extracted diagnoses for OA and 67 common chronic conditions. We included individuals aged 40+ years on 31 December 2007, with incident OA between 2008 and 2009. We selected references without OA, matched on birth year, sex, and year of death or moving outside the region. We employed group-based trajectory modelling to capture morbidity count trajectories from 1998 to 2019. Individuals without any comorbidity were included as a reference group but were not included in the model. RESULTS: We identified 9846 OA cases (mean age: 65.9 (SD 11.7), female: 58%) and 9846 matched references. Among both cases and references, 1296 individuals did not develop chronic conditions (no-chronic-condition class). We identified four classes. At the study outset, all classes exhibited a low average number of chronic conditions (≤1). Class 1 had the slowest progression towards multimorbidity, which increased progressively in each class. Class 1 had the lowest count of chronic conditions at the end of the follow-up (mean: 2.9 (SD 1.7)), while class 4 had the highest (9.6 (2.6)). The presence of OA was associated with a 1.29 (1.12, 1.48) adjusted relative risk of belonging to class 1 up to 2.45 (2.12, 2.83) for class 4. CONCLUSIONS: Our findings suggest that individuals with OA face an almost threefold higher risk of developing severe multimorbidity.