title: Does adhesive capsulitis of the shoulder increase the risk of stroke? A population-based propensity score-matched follow-up study.
abstract: OBJECTIVE
  A previous population-based study reported an increased risk of stroke after the occurrence of adhesive capsulitis of the shoulder (ACS), but there were substantial imbalances in the distribution of age and pre-existing vascular risk factors between subjects with ACS and without ACS, which might lead to a confounded association between ACS and stroke. The purpose of the present large-scale propensity score-matched population-based follow-up study was to clarify whether there is an increased stroke risk after ACS.
  
  
  METHODS
  We used a logistic regression model that includes age, sex, pre-existing comorbidities and socioeconomic status as covariates to compute the propensity score. A total of 22025 subjects with at least two ambulatory visits with the principal diagnosis of ACS in 2001 was enrolled in the ACS group. The non-ACS group consisted of 22025, propensity score-matched subjects without ACS. The stroke-free survival curves for these 2 groups were compared using the Kaplan-Meier method. Stratified Cox proportional hazard regression with patients matched on propensity score was used to estimate the effect of ACS on the occurrence of stroke.
  
  
  RESULTS
  During the two-year follow-up period, 657 subjects in the ACS group (2.98%) and 687 in the non-ACS group (3.12%) developed stroke. The hazard ratio (HR) of stroke for the ACS group was 0.93 compared to the non-ACS group (95% confidence interval [CI], 0.83-1.04, P = 0.1778). There was no statistically significant difference in stroke subtype distribution between the two groups (P = 0.2114).
  
  
  CONCLUSIONS
  These findings indicate that ACS itself is not associated with an increased risk of subsequent stroke.
authors.affiliation: Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital Yun-Lin Branch, Yunlin, Taiwan.
authors.forename: Chueh-Hung
authors.initials: CH
authors.lastname: Wu
authors.forename: Yen-Ho
authors.initials: YH
authors.lastname: Wang
authors.forename: Ya-Ping
authors.initials: YP
authors.lastname: Huang
authors.forename: Shin-Liang
authors.initials: SL
authors.lastname: Pan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002062:Bursitis / Q000150:complications* / Q000453:epidemiology; D015897:Comorbidity; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D057216:Propensity Score; D016016:Proportional Hazards Models; D012307:Risk Factors; D012782:Shoulder / Q000473:pathology*; D020521:Stroke / Q000453:epidemiology / Q000209:etiology*; D015996:Survival Rate; D013624:Taiwan / Q000453:epidemiology