Factors related to the evolution of Health Related Quality of Life in coronary patients. A longitudinal approach using Weighted Generalized Estimating Equations with missing data

Abstract

BackgroundThe aim is to know the factors related to the evolution of Health Related Quality of Life (HRQL) in Coronary Patients (CP) from a longitudinal perspective using an appropriate method that handles missing data adequately when the mechanism of missingness is uncertain. MethodsProspective study with repeated measures at baseline, 3 and 6months. 250 patients with acute myocardial infarction or unstable angina were studied. Sociodemographic and clinical data were collected at baseline. Mental health (GHQ-28) and HRQL (SF-36v1) were assessed during the follow-up. The missingness mechanism was tested. Friedman test and partial eta-squared were used to analyse changes in SF-36 scores and WGEE were used to identify the predictors of the evolution of HRQL. Results95 dropped out after 3months and 72 after 6months. The missingness was likely to be at random. All the dimensions of the SF-36 improved over time, except PF. The factors related to the evolution of HRQL were: being woman (B=−23.9 in RE; B=−6.9 in MCS), older age (B=−0.5 in BP; B=−0.3 in VT), being single/separated (B=−14.5 in GH; B=−14.1 in SF; B=−23.3 in MH) and widow(er) (B=−23.2 PF; B=−29.8 in SF), hypertensive (B=−19.8 in RP; B=−8.9 in VT), worse mental health (B=−3 in PF; B=−2.8 in RP; B=−3.1 in BP; B=−1.2 in PCS; B=−3.8 in VT; B=−2.6 in SF), previous history of CHD (B=−12.5 in PF; B=−5.2 in PCS), and performing heart-healthy physical activities (B=13.9 in PF). ConclusionsHRQL improves over time. A global approach, including age, marital status, performing physical activities or hypertension, is required to improve HRQL in CP.