[Effectiveness of antihypertensive treatment and control of blood pressure: is it improvable?]

Reliability and Validity of the Treatment Satisfaction with Medicines Questionnaire (SATMED-Q) in Persons with Arterial Hypertension

OBJECTIVE

To evaluate the reliability and validity of the Treatment Satisfaction with Medicines Questionnaire (SATMED-Q) in persons with arterial hypertension undergoing pharmacological treatment, along with its convergent validity with degree of control of blood pressure levels, therapeutic adherence, and tolerability of antihypertensive drugs.

METHODS

Observational cross-sectional study conducted on a sample of 484 persons. Treatment satisfaction was evaluated with the SATMED-Q, an instrument consisting of 17 items with six dimensions. Other variables were blood pressure, antihypertensive drugs, adverse effects, therapeutic adherence, and participants' characteristics.

RESULTS

Cronbach's alpha was 0.916. Factor analysis revealed six factors that could account for 89.97% of total variance. The test-retest reliability analysis yielded an intraclass correlation coefficient of 0.910 (95% CI = 0.806-0.959). In a possible range of 0 through 100 points, participant satisfaction with treatment ranged from 38.2 to 100 (mean 79.9 (SD = 12.9; 95% CI = 78.8-81.0); median 80.9). SATMED-Q scores were higher among persons who reported experiencing no adverse effects (82.5 ± 11.6 SD vs. 68.7 ± 11.9 SD; p < 0.001). Satisfaction levels were significantly lower among subjects not complying with the treatment (73.2 ± 12.9 vs. 82.1 ± 12.1; p < 0.001), and significantly higher among those presenting with controlled blood pressure levels (82.1 ± 12.1 SD vs. 77.5 ± 13.3 SD; p < 0.001).

CONCLUSIONS

The SATMED-Q showed high internal consistency and good stability in the reliability analysis. It is an appropriate instrument for evaluating satisfaction with antihypertensive treatment, both in routine clinical practice and in community pharmacy or clinical research settings.