Study Design
This was a cross-sectional study based on questionnaires. The questionnaires were structured and shared using the digital platform Google Forms and were conducted between 02 and 12 June 2020. The questionnaires were self-administered in Portuguese language and contained six sections as described below.
Questionnaires
The first section dealt with general data regarding the participant demographics . It contained questions related to sex (men or women), age (open-ended question), body mass (open-ended question), height (open-ended question), total family income measured in multiples of the minimum wage (less than 1 minimum wage, minimum wage between 1-2, minimum wage between 3-6, minimum wage between 7-10, more than 11 minimum wages). For analysis purposes, scores from 0 to 4 were assigned to total family income, where 0 referred to the lowest income (less than 1 minimal wage) and 4 to the highest family income (more than 10 minimal wage).
The second section contained questions related to behavior during quarantine regarding to individual’s level of restriction concerning routine activities (taking complete measures of social distancing and did not go out to perform any activity, leaving only for essential non-work activities, leaving only for essential activities including work activities, and not taking any measures of social distancing) . For analysis purposes, scores from 0 to 3 were assigned to individual’s level of restriction, where 0 referred to the higher restriction level and 3 to the lower restriction level. The second section also contain questions for how many days he or she adopted the social distancing measures (less than 30 days, between 30-45 days, between 46-60 days, between 61-75 days, between 76 -90 days, more than 91 days). For analysis purposes, scores from 0 to 5 were assigned to the duration of the social distancing measurements adopted, where 0 referred to the lower duration (less than 30 days) and 5 to the higher duration (more than 91 days).
The third section was dedicated to assessing the volunteers' current physical activity level. To this end, the International Physical Activity Questionnaire (IPAQ) proposed by the World Health Organization in 1998 was used. This instrument has acceptable measurement properties for estimating physical activity levels with previously reported internationally validated results [25] and was validated for the Portuguese language in 2001 [26, 27]. According to the answers provided by the participants, the level of physical activity was classified into 5 categories according to Matsudo et al (2001)[27]: very active (those who perform vigorous activities 5 days/week and ≥30 min per session or vigorous activities ≥3 days/week and ≥20 min per session + moderate activities ≥5 days/week and ≥30 min per session), active (those who perform vigorous activities ≥3 days/week and ≥20 min per session; or moderate activities ≥5 days/week and ≥30 min per session; or any combined activity: ≥5 days/week and ≥150 min/week such as walking + moderate + vigorous), irregularly active A (those who perform physical activities but it is insufficient to be classified as active because it does not comply with the recommendations regarding frequency or duration), irregularly active B (those who perform physical activity but it is insufficient to be classified as irregularly active A because it does not comply with either the frequency or duration recommendations), not active (those who do not perform any physical activity for at least 10 continuous minutes during the week). For the purpose of analysis, scores from 0 to 4 were assigned to activity levels, where 0 referred to the lowest level of activity (not active) and 4 to the highest level of activity (very active).
The fourth section aimed to screen for possible mood disorders. The Patient Health Questionnaire-9 (PHQ-9) and General Anxiety Disorder-7 (GAD-7) questionnaires were applied. PHQ-9 is an instrument, validated for Portuguese, which is widely used to identify individuals at risk of depression [28, 29]. The questionnaire provides a final score ranging from 0 to 27. Scores of ≤4 suggest minimal depression, scores from 5 to 9 suggest mild depression, scores from 10 to 14 suggest moderate depression, scores from 15 to 19 suggest moderately severe depression, and scores of 20 or greater suggest severe depression. For the purpose of analysis, scores from 0 to 4 were assigned to the levels of depression, where 0 referred to the lowest level of depression (minimal depression) and 4 to the highest level of depression (severe depression). GAD-7 aims to identify possible generalized anxiety disorders and also has a validated Portuguese version [30, 31]. The questionnaire provides a final score ranging from 0 to 21. Scores of ≤ 4 suggest no anxiety disorder, scores from 5 to 9 suggest mild anxiety, scores from 10 to 14 suggest moderate anxiety and scores of 15 or greater suggest severe anxiety disorder. For the purpose of analysis, scores from 0 to 3 were assigned to the anxiety levels, where 0 referred to the lowest level of anxiety (no anxiety disorder) and 3 to the highest level of anxiety (severe anxiety disorder).
The last section again used the IPAQ questionnaire to assess physical activity. However, unlike the third section, the questions concerned the exercise routine in the period prior to quarantine and the recommended social distancing measures (prior to March, 2020). To analyze the effect of social distancing on the level of physical activity, the difference in the level of physical activity was calculated as the IPAQ score obtained in the current condition minus the score obtained according to the condition before the period of social distancing (ΔIPAQ). For analysis purposes, scores from -1 to 1 were assigned to the difference in the level of physical activity between current and previous pandemic level, where -1 referred to a reduction in the physical activity level, 0 referred to no difference in physical activity level, and 1 referred to an increase in physical activity level.
Participants
Participants were invited to partake in the study through websites, e-mail, and social networks (Instagram, Facebook, and Whatsapp) of the researchers and institutions involved.
The inclusion criteria were being literate, over 18 years of age, and being familiar with online questionnaires. Exclusion criteria were those who did not complete the questionnaire or answered it inappropriately. Individuals from 26 Brazilian states and the Federal District answered the questionnaire. Table 1 shows the description of the sample.
A total of 2,140 questionnaires were answered voluntarily. Among them, 287 were excluded for not meeting the inclusion criteria totaling 1,853 (1,110 female and 743 male) selected participants, as shown in Figure 1.
Table 1 - Descriptive characteristics of participants.
Variables
|
Male
N = 743
|
Female
N = 1110
|
t and p value
|
Effect size
|
CI (95%)
|
Age (years)
|
39.7 ± 12.2
|
37.9 ± 12.4*
|
t (1851) = 3.00
p < 0.001
|
d = 0.14
|
0.07 to 0.21
|
Body mass (kg)
|
81.0 ± 12.6
|
65.0 ± 11.5*
|
t (1842) = 28.17
p < 0.001
|
d = 1.32
|
1.00 to 1.60
|
Body height (cm)
|
176.8 ± 6.9
|
163.5 ± 6.2*
|
t (1851) = 42.70
p = 0.003
|
d = 1.99
|
1.50 to 2.50
|
Values were expressed as mean ± SD. * p < 0.05; t (t test value); d (cohen’s d); CI (confidence interval); WHO5 (World Health Organization Well-Being Index).
Statistical analysis
According to the Kolmogorov-Smirnov test, no variables presented a normal distribution. Variables were expressed as median and interquartile range. Categorical variables were expressed in absolute numbers and/or percentages. The Mann-Whitney test was used to verify differences between sexes according to age, body mass and height. The measurements of the effect size were calculated by dividing the mean difference by the standard deviation. The magnitude of the effect sizes was judged according to the following criteria: d=0.2 considered a ‘small’ effect size; 0.5 represented a ‘medium’ effect size; and 0.8 a ‘large’ effect size [32]. For comparison between sexes and family income, IPAQ at social distancing period, PHQ-9, GAD-7, and ΔIPAQ, a chi-square test was employed. Chi-square tests were also employed in order to compare PHQ-9 and GAD-7 with IPAQ during the social distancing period, ΔIPAQ, and family income. Data were grouped so that all expected frequencies were higher than five. The Kruskal-Wallis test was used to verify age differences between each level of the PHQ9 and GAD7 questionnaire. The Kruskal-Wallis test was complemented by post hoc tests (pairwise analysis). Statistical analysis was performed using SPSS v 21.0 (Chicago, Illinois, USA). In all comparisons, p values < 5% were considered statistically significant.