Reliability and validity of the Treatment Satisfaction Questionnaire for Medication among Portuguese-speaking Brazilian patients with hypertension

Abstract

Aims and objectives: This study examined the reliability and validity of the Brazilian Portuguese version of the Treatment Satisfaction Questionnaire for Medication (version 1.4) among patients with hypertension. Understanding the patient experience with treatment satisfaction will contribute to improved medication adherence and control of hypertension.

Background: Hypertension is a serious problem in Brazil that is associated with chronic illness controlled, in part, by consistent adherence to medications. Patient satisfaction with medication treatment is associated with adherence to medication. The Treatment Satisfaction Questionnaire for Medication (version 1.4) is a promising instrument for measuring medication; however, to date there has been no report of the reliability and validity of the instrument with Portuguese-speaking adults with hypertension in Brazil.

Design: Cross-sectional descriptive exploratory study.

Methods: A convenience sample of 300 patients with hypertension in an outpatient setting in the southeast region of São Paulo state in Brazil completed the Treatment Satisfaction Questionnaire for Medication (version 1.4). The instrument, comprised of four subscales, was evaluated for reliability using correlation analyses and internal consistency. Confirmatory factor analysis was used to determine factorial validity.

Results: Correlational analyses, internal consistency (Cronbach's alpha) and hierarchical confirmatory factor analysis demonstrate adequate support for the four-factor dimensionality, reliability and factorial validity of the Treatment Satisfaction Questionnaire for Medication (version 1.4).

Conclusions: This study provides modest evidence for internal consistency and factorial validity of the Treatment Satisfaction Questionnaire for Medication (version 1.4) in Portuguese-speaking adult Brazilians with hypertension. Future testing should focus on extending reliability testing, discriminant validity and potential translation and literacy issues in this population.

Relevance to clinical practice: Within known limitations, clinicians will find the Treatment Satisfaction Questionnaire for Medication (version 1.4) useful for identifying adult Portuguese-speaking Brazilian patients at risk of poor adherence and tailoring adherence interventions to promote hypertension control.

Keywords: Brazil; hypertension; patient satisfaction; psychometrics instrumentation; reliability; validity.