Promoção de atividade física em indivíduos após um Acidente Vascular Encefálico

Abstract

Individuals after a stroke are more likely to develop a new event. Therefore, engaging in activities that reduce this risk is essential for this population. Approximately 90% of the risk factors for stroke are modifiable. Among these, physical activity appears to play a key role in reducing new cardiovascular events. However, only about 30% of individuals after a stroke are physically active. It is essential that interventions focus on promoting long-term physical activity to promote behaviour change in this population. Studies indicate that self-management programs that consider theoretical frameworks and behaviour change techniques may have the potential to promote long-term physical activity. Therefore, the overall objective of this thesis was to evaluate the potential effect of a self-management program for promoting physical activity in individuals after a stroke. To facilitate its implementation, some preliminary studies were conducted, such as the translation and analysis of the measurement properties of a scale that assesses self-efficacy for physical exercise after stroke. Furthermore, to support future studies, a study evaluating the measurement properties of two physical activity monitors was developed. The first study in this thesis refers to a methodological study that aimed to translate and cross-culturally adapt the English version of the Self-Efficacy for Exercise scale into Brazilian Portuguese. The translation and cross-cultural adaptation process of the scale was carried out in six stages: (1) translation; (2) synthesis; (3) back-translation; (4) review by a committee of experts; (5) pre-test; and (6) approval by the authors who developed the instrument. The results demonstrated that all six stages necessary for the scale to be translated and cross-culturally accepted were completed satisfactorily, enabling its use in the Brazilian population. The second study is a methodological study that aimed to investigate the test-retest reliability, standard error of measurement, and minimum detectable change of the translated version of the Self-Efficacy for Exercise-Brazil scale. Post-stroke individuals aged 18 years or older who did not present cognitive changes were included. The scale was administered twice with a 4- to 10-day interval between measurements. Test-retest reliability was calculated using the Intraclass Correlation Coefficient (ICC). The standard error of measurement was calculated and reported in points and percentage error, and the minimum detectable change was calculated and reported in points. The test-retest reliability of the scale was considered good, with an intraclass correlation coefficient of 0.85 (95% CI: 0.75–0.91). The standard error of measurement was 1.08 points, representing a 20% percentage error, and the minimum detectable change was 2.99 points. The Self-Efficacy for Exercise-Brazil scale showed adequate test-retest reliability and measurement error. Finally, a 3-point change on the scale can be interpreted as a real change. The third and fourth studies refer to the protocol and the pilot randomized clinical trial, respectively, developed to assess whether a home-based self-management program has the potential to promote physical activity more than usual care, in the short and long term. Individuals less than 6 months post-stroke, aged 18 years or older, physically inactive, and with mild deficits were included. They were randomized into two groups: experimental and control. The experimental group received six 60-minute home-based self-management sessions and usual care over 3 months. The control group received one 60-minute stroke education session and usual care over 3 months. The primary outcome measure was physical activity level, measured by the number of steps per day. Two-way ANOVA was used to assess statistically significant differences between groups. Clinically important differences were assessed by observing the mean differences between groups. Twenty-four individuals (67 ± 11 years) were included. Two-way ANOVA revealed no statistically significant differences between groups in either the short or long term. Regarding clinically important differences, in the short term, there was a clinically important difference between the groups of 1,380 steps per day (95% CI: -161 to 2,921). However, in the long term, this difference did not remain clinically relevant, at 842 steps per day (95% CI: -1,621 to 3,305). Future studies should adjust the intervention protocol to maintain physical activity levels in the long term. Finally, the fifth study refers to a methodological study that aimed to investigate the criterion validity and accuracy of two physical activity monitors (Actigraph and Xiaomi) for counting steps in individuals after a stroke. Post-stroke individuals aged 18 years or older, able to walk, and without cognitive impairment were included. Individuals performed the 2-Minute Walk Test (2MWT) using the Actigraph and Xiaomi simultaneously on the non-paretic upper limb. The 2MWT was videotaped, and a physical therapist performed step counts based on the recordings. Criterion validity was assessed using Spearman's correlation coefficient (rho), which compared the number of steps estimated by the physical activity monitors with the physical therapist's count. To assess the accuracy of the monitors, the absolute error and the percentage error were calculated. Fifty individuals (64 ± 11 years) were included. The steps estimated by Actigraph demonstrated low correlation (rho 0.41; 95% CI: 0.15 to 0.62) and a high absolute error rate of 39% (95% CI: 33 to 45) when compared with the step count performed by the physiotherapist. The steps estimated by Xiaomi demonstrated high correlation (rho 0.83; 95% CI: 0.72 to 0.90) and a moderate absolute error rate of 12% (95% CI: 6 to 19) when compared with the step count performed by the physiotherapist.