Predictors of Quality of Life in Transfusion-dependent Thalassemia Patients Based on the PRECEDE Model: A Structural Equation Modeling Approach

This study aimed to determine the predictors of Quality of Life (QoL) in Transfusion-Dependent Thalassemia (TDT) patients
based on PRECEDE (Predisposing, Reinforcing and Enabling Constructs in Educational Diagnosis and Evaluation) model. This
cross-sectional analytical study was performed on 389 TDT patients who were under treatment in four thalassemia centers in
Tehran, Iran. Data gathering instrument consisted of three parts: socioeconomic and demographic information, the Persian
version of the six standardized questionnaires for measuring some of the potential predictive factors of QoL in TDT patients
based on the PRECEDE model constructs, and a researcher-made questionnaire to assess knowledge of patients about health-
and QoL-promoting behaviors and enabling factors involved in health- and QoL-promoting behaviors. Using AMOS 23.0, the
structural equationmodeling withmaximum likelihood estimation was conducted to test the proposed hypotheses. Associations
of QoL with all of the PRECEDE model constructs, including anxiety–depression, self-efficacy, perceived barriers, knowledge,
enabling factors, and reinforcing factors were significant (all p < 0.001). Anxiety–depression and perceived barriers were the
significant negative predictors of QoL in TDT patients, whereas health-promoting lifestyle was the significant positive predictor
of QoL in TDT patients.The final conceptual model of the study was adequately fit and can be applied as a framework for future
educational-supportive programs aimed at improving the QoL in TDT patients.