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

Background: The 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. Methods: Prospective study with repeated measures at baseline, 3 and 6 months. 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. Results: 95 dropped out after 3 months and 72 after 6 months. 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). Conclusions: HRQL improves over time. A global approach, including age, marital status, performing physical activities or hypertension, is required to improve HRQL in CP. (C) 2016 Elsevier Ireland Ltd. All rights reserved.