Reasons why osteoarthritis predicts mortality:Path analysis within a Cox proportional hazards model

Objectives To identify potentially modifiable factors that mediate the association between symptomatic osteoarthritis (OA) and premature mortality. Methods A population-based prospective cohort study; primary care medical record data were linked to self-report information collected by questionnaire in adults aged 50 years and over (n=10 415). OA was defined by primary care consultation and moderate-to-severe pain interference in daily life. A Cox proportional hazards analysis determined the total effect (TE) of OA on mortality after adjustment for potential confounders. Within the Cox model, path analysis was used to decompose the TE to assess the indirect and direct effects for selected potential mediators (anxiety, depression, unrefreshed sleep and walking frequency). Results are expressed as HRs with 95% CIs derived from bootstrap resampling. Results OA was significantly associated with mortality (TE-adjusted HR 1.14; 95% CI 1.00 to 1.29). The indirect effects for walking frequency were 1.05 (95% CI 1.04 to 1.06), depression 1.02 (95% CI 1.02 to 1.03), anxiety 1.01 (95% CI 1.00 to 1.02) and unrefreshed sleep 1.01 (95% CI 1.00 to 1.01). Conclusions The analysis indicates that encouraging people to walk and get out and about' in addition to targeting OA could be protective against excessive mortality. The findings also suggest that depression, anxiety and unrefreshed sleep have a role in premature mortality for people with OA; however, this has low clinical significance

Identifying Long-Term Trajectories of Foot Pain Severity and Potential Prognostic Factors: A Population-Based Cohort Study.

ObjectivesTo identify distinct foot pain trajectories over 7 years and examine their associations with potential prognostic factors.MethodsAdults ages ≥50 years and registered with 4 general practices in North Staffordshire, UK were mailed a baseline health survey. Those reporting current or recent foot pain were invited to attend a research assessment clinic. Follow-up was by repeated postal surveys at 18, 36, 54, and 84 months. Distinct trajectories of foot pain were explored using latent class growth analysis (LCGA). Subsequently, identified trajectories were combined into most and least progressive groups, and covariate-adjusted associations with a range of prognostic factors were examined.ResultsOf 560 adults with foot pain attending baseline research clinics, 425 (76%) provided data at baseline and 2 or more follow-up time points. LCGA for foot pain severity (0-10 numerical rating scale) identified a 4-trajectory model: "mild, improving" (37%); "moderate, improving" (33%); "moderate-severe, persistent" (24%); and "severe, persistent" (6%). Compared with individuals in more favorable (improving) pain trajectories, those in less favorable (persistent) pain trajectories were more likely to be obese, have routine/manual and intermediate occupations, have poorer physical and mental health, have catastrophizing beliefs, have greater foot-specific functional limitation, and have self-assessed hallux valgus at baseline.ConclusionsFour distinct trajectories of foot pain were identified over a 7-year period, with one-third of individuals classified as having pain that is persistently moderate-severe and severe in intensity. The effect of intervening to target modifiable prognostic factors such as obesity and hallux valgus on long-term outcomes in people with foot pain requires investigation

252 The prevalence of axial involvement in psoriasis or psoriatic arthritis: a systematic review and meta-analysis

Background: A significant proportion of patients with psoriasis (PsO) or psoriatic arthritis (PsA) have axial involvement which is associated with more severe peripheral arthritis in PsA. Historically, methods for recognition of axial involvement in psoriatic disease (AxPsA) have varied as different definitions have been used to define axial disease. This is the first attempt to derive a robust prevalence estimate of AxPsA in adult patients with PsO or PsA fulfilling the ClASsification for Psoriatic ARthritis (CASPAR) criteria, and explore variation in prevalence by criteria used to define AxPsA.Methods: Five electronic databases were searched using a search strategy combining key words and related database-specific subject terms to identify relevant cross-sectional, case-control or longitudinal studies published since the introduction of the CASPAR criteria in 2006. Prevalence figures and 95% confidence intervals (CIs) were extracted or calculated. Included articles were assessed for risk of bias by two independent reviewers. The Cochran Q statistic was used to assess the presence of heterogeneity. Furthermore, I2 statistic was calculated to examine the proportion of variation in the study estimates that could be explained by heterogeneity. Meta-analyses were undertaken using random-effects models.Results: Twenty-two articles met the eligibility criteria. In patients with established PsA, prevalence estimates for radiographic sacroiliitis ranged from 11% to 46%. The random-effects pooled prevalence was 29% (95% CIs: 24-35) (Table). When only studies defining sacroiliitis using the modified New York criteria (mNYc) for ankylosing spondylitis (AS) and at low risk of bias were pooled, prevalence increased to 33% (95% CIs: 29-37) with reduced but still significant heterogeneity. It was possible to stratify prevalence of radiographic sacroiliitis by sex in five studies. Prevalence was higher for men in all studies with male-to-female prevalence ratios ranging from 1.28 to 2.03. In PsO patients, the prevalence of radiographic sacroiliitis was much lower than in PsA, including two studies reporting mNYc defined sacroiliitis prevalence of 2.8% and 6.0%

183. GOUT AS A CONSEQUENCE OF SLEEP APNOEA: A MATCHED COHORT STUDY

Background: Gout and obstructive sleep apnoea are both common problems in primary care and associated with considerable co-morbidity. Serum uric acid levels are frequently elevated in sleep apnoea patients and one previous cohort study found that people with sleep apnoea are at increased risk of gout during the first year after diagnosis. This study aimed to examine the association between sleep apnoea and subsequent development of gout over a longer follow-up period.Methods: This was a matched retrospective cohort study undertaken in the UK Clinical Practice Research Datalink (CPRD). Individuals aged 18 years and over with an incident diagnosis of sleep apnoea between 1990 and 2010 were identified and followed-up until 2015. Each sleep apnoea case was matched to four age-, gender- and GP-practice matched controls. Incidence rates of gout were calculated per 1000 person-years and hazard ratios (HR) estimated using Cox regression adjusted for body mass index (BMI), diabetes mellitus, ischaemic heart disease, hypertension, hyperlipidaemia, diuretic use, alcohol use and smoking. Risk of incident gout was assessed at different time-points: 1, 5 and 10 years. Furthermore, analyses were stratified by BMI categories (normal BMI<25kg/m2, overweight BMI 25-30kg/m2, obese BMI ≥30kg/m2).Results: The study sample consisted of 15,878 individuals with sleep apnoea and 63,283 controls: median follow-up was 8.03 years. 782 (5.2%) of cases and 1,640 (2.3%) of controls developed gout. Incidence rate of gout per 1000 person-years was 7.83 (95% CI 7.29, 8.40) among those with sleep apnoea and 4.00 (3.80, 4.19) among those without [adjusted HR 1.32 (1.20, 1.45)]. At 1, 2 and 5 years of follow-up, adjusted HRs for incident gout were 1.37 (1.07, 1.75), 1.41 (1.19, 1.69) and 1.36 (1.17, 1.57) respectively. Gout incidence rates per 1000 person-years were higher among those with sleep apnoea across BMI categories and increased with higher BMI in both exposure groups, however proportionately more so in the controls, resulting in both crude and adjusted HRs to decrease with increasing BMI: 1.74 (1.22, 2.48), 1.25 (1.05, 1.49), 1.23 (1.09, 1.41) for normal, overweight and obese categories.Conclusion: The novelty of this study lies in assessing both short and long term association of sleep apnoea with incident gout in a large primary care setting population. People with sleep apnoea continued to be at higher risk of developing gout beyond the first year after sleep apnoea diagnosis. Furthermore, the independent risk of gout conferred by sleep apnoea appears to be larger in those with normal BMI

Risk of fracture among patients with polymyalgia rheumatica and giant cell arteritis: a population-based study

Abstract Background Glucocorticoids are associated with increased fracture risk and are the mainstay of treatment in polymyalgia rheumatica (PMR) and giant cell arteritis (GCA). However, fracture risk in these conditions has not been previously quantified. The aim of this study was to quantify the risk of fracture among patients with PMR and GCA. Methods A retrospective cohort study was conducted using primary care records from the UK-based Clinical Practice Research Datalink. Individuals aged 40 years and over, with incident diagnoses of PMR or GCA were separately identified from 1990–2004 and followed up until 2015. For each exposed individual, four age-, sex- and practice-matched controls were randomly selected. Incidence rates of fracture per 10,000 person-years were calculated for each disease group and hazard rates were compared to the unexposed using Cox regression models. Results Overall, 12,136 and 2673 cases of PMR and GCA, respectively, were identified. The incidence rate of fracture was 148.05 (95% CI 141.16–155.28) in PMR and 147.15 (132.91–162.91) in GCA per 10,000 person-years. Risk of fracture was increased by 63% in PMR (adjusted hazard ratio 1.63, 95% CI 1.54–1.73) and 67% in GCA (1.67, 1.49–1.88) compared to the control populations. Fewer than 13% of glucocorticoid-treated cases were prescribed bisphosphonates. Conclusions This study reports, for the first time, a similar increase in fracture risk for patients with PMR and GCA. More needs to be done to improve adherence to guidelines to co-prescribe bisphosphonates. Further research needs to identify whether lower glucocorticoid starting doses and/or aggressive dose reduction reduces fracture risk

一种实时自适应步进电机PID控制器设计

传统PID控制器通常难以满足多变量、非线性、强耦合的步进电机动态响应和精确调速要求,结合传统PID控制和模糊控制及遗传算法(GA)整定PID参数的优点,设计基于模糊遗传算法的实时自适应步进电动机PID控制器,充分发挥传统和智能控制策略各自的优势。仿真结果表明,该实时自适应步进电动机PID控制器,具有很好的自适应能力和抗负载扰动能力。在稳定性、动态速度响应诸方面均优于传统的PID控制器和模糊控制器,系统达到了较高调速性能和控制精度

Additional file 3: of Impairment-targeted exercises for older adults with knee pain: a proof-of-principle study (TargET-Knee-Pain)

Question content and response options of secondary outcome measures. Format of individual questions used to measure secondary outcomes. (DOCX 14 kb

Additional file 2: of Risk of fracture among patients with polymyalgia rheumatica and giant cell arteritis: a population-based study

Algorithm for deriving glucocorticoid average dose and duration. (DOCX 22 kb

Additional file 1: Table S1. of Risk of fracture among patients with polymyalgia rheumatica and giant cell arteritis: a population-based study

Read codes for exposure and outcome definition. (DOCX 13 kb