Patients' information needs and perceptions of medicines and illness: A multi-method approach to develop and validate measures in Portugal

This thesis aimed to adapt a survey tool to measure patients’ desires for information (EID), perceptions about medicines (PHM and PBM) and anxiety about illness (Ai and Ti) from the UK to Portugal and to explore how perceptions impact on medicines taking behaviours in different care settings. The survey tool was adapted using a multi-method approach comprising translation and back-translation, rating of equivalence, and assessment of understanding in various stages of revision. The tool was tested in a patient sample recruited in different care settings in Portugal and the UK and responses were used to explore validity and reliability. Data was used to compare scores to the scales between patient samples and to investigate factors influencing adherence behaviours. The survey tool was modified during validation, where the Ti scale was dropped for its validity and reliability. Four factors emerged in the course of factor analysis. One item was dropped in the PBM and PHM scales, which were weighed for comparison. Internal consistency of the Ai (α=0.756) and PBM (α=0.695) scales were good, while the EID (α=0.607) and PHM (α=0.536) were acceptable. All scales, except the EID, were consistent over time [p(r)0.05]. Portuguese, community recruited, female, higher educated and younger patients tended to desire more information. Patients prescribed more medicines tended to perceive medicines as more harmful. Anxiety tended to be higher in hospitalized patients, the elderly and lower educated and those prescribed more medicines. Patients feeling more anxious (ϱ=0.420; p=0.000) and perceiving their health status as bad (ϱ=-0.213 p=0.000) tended to perceive a greater harm from medicines. Logistic modelling showed that patients aged > 60 [Adj.OR=2.20 {1.38-3.53}] and patients scoring > 17 on the EID scale [Adj.OR=2.57; {1.36-4.84}] were more likely to be compliant (p