Mental distress and its associations with behavioral outcomes during the COVID-19 pandemic: a national survey of Chinese adults.

OBJECTIVES: This study aimed to evaluate associations between mental distress and COVID-19-related changes in behavioral outcomes and potential modifiers (age, gender, educational attainment) of such associations. STUDY DESIGN: This was a cross-sectional study. METHODS: An online survey using anonymous network sampling was conducted in China from April to May 2020 using a 74-item questionnaire. A national sample of 10,545 adults in 31 provinces provided data on sociodemographic characteristics, COVID-19-related mental distress, and changes in behavioral outcomes. Structural equation models were used for data analyses. RESULTS: After adjusting for covariates, greater mental distress was associated with increased smoking (odds ratio [OR] = 1.42, 95% confidence interval [CI]: 1.20-1.68 and OR = 1.54, 95% CI: 1.31-1.82 per one standard deviation [SD] increase in mental distress) and alcohol consumption (OR = 1.67, 95% CI: 1.45-1.92 and OR = 1.47, 95% CI: 1.24-1.75 per one SD increase in mental distress) among current smokers and drinkers and with both increased and decreased physical activity (ORs ranged from 1.32 to 1.56). Underweight adults were more likely to lose body weight (≥1 kg; OR = 1.63, 95% CI: 1.30-2.04), whereas overweight adults were more likely to gain weight (OR = 1.61, 95% CI: 1.46-1.78) by the same amount. Association between mental distress and change in physical activity was stronger in adults aged ≥40 years (ORs ranged from 1.43 to 2.05) and those with high education (ORs ranged from 1.43 to 1.77). Mental distress was associated with increased smoking in males (OR = 1.60, 95% CI: 1.37-1.87) but not females (OR = 1.11, 95% CI: 0.82-1.51). CONCLUSIONS: Greater mental distress was associated with some positive and negative changes in behavioral outcomes during the pandemic. These findings inform the design of tailored public health interventions aimed to mitigate long-term negative consequences of mental distress on outcomes.

The effect of variable practice on wheelchair propulsive efficiency and propulsive timing.

AIM: The net mechanical efficiency of wheelchair propulsion is very low, approximately 13%. It is necessary to look for effective practice methods to obtain greater output with less energy expenditure during wheelchair propulsions. Literature indicates that variable practice (VP) is more effective than constant practice (CP) in motor-skill learning. However, it is unknown if VP is more effective than CP in improving wheelchair propulsive efficiency. The purpose of the study was to determine how propulsive efficiency and propulsive timing were affected by variable practice and constant practice. DESIGN: This was an observational and experimental study. SETTING: The experiment was conducted in a well-controlled university research laboratory. POPULATION: A total of 33 able-bodied subjects participated in this study. METHODS: Participants were randomly placed into one of the three training groups, two constant practice groups and one variable practice group. One constant group practiced wheelchair propulsion on a roller system with a single speed, 30% of the maximum speed, while the other constant group practiced using 55% of the maximum speed. The variable group practiced with both speeds. Three dependent variables, propulsive efficiency, timing, and intercycle variability of the timing, were measured. RESULTS: All groups improved the three dependent variables significantly after the training, and in general the VP group had greater improvement than the others in improving the propulsive efficiency. CONCLUSION: This study is the first to demonstrate the advantage of the VP over the CP in improving the propulsive efficiency. CLINICAL REHABILITATION IMPACT: This finding has great implication for paraplegics because they require greater workloads for upper-extremity activities.