Transitional Employment and Psychological Distress: a Longitudinal Study

Assessing the Smallest Detectable Change of the Kessler Psychological Distress Scale Score in an Adult Population in Japan

Background

Psychological distress is prevalent worldwide and can lead to the development of mental conditions such as major depression and anxiety disorders. It is essential to assess the severity of patient-reported outcomes to provide effective treatment for psychological distress. The Kessler Psychological Distress Scale (K6) is one of the most widely used psychological distress scales. However, the smallest detectable change (SDC) of the K6 score has not been elucidated. Therefore, the current study aimed to determine the SDC of the K6 score in a Japanese adult population.

Methods

Participants aged 20-59 years who are native Japanese speakers were recruited from the panel list of a web research firm. The K6 score was assessed at baseline (T1) and at 2-week follow-up (T2). SDCs were calculated at the individual (SDC_ind) and group (SDC_group) levels. Intraclass correlation coefficient agreement (ICC_agreement) was calculated to assess test-retest reliability and Cronbach's alpha to evaluate internal consistency.

Results

A total of 3254 (1627 [50%] female) responded at T1 and T2. The mean (standard deviation) K6 scores were 5.71 (5.84) at T1 and 5.65 (5.83) at T2. The SDC_ind and SDC_group of the K6 score were 8.47 (35.31%) and 0.15 (0.63%), respectively. The ICC_agreement was 0.73, and the Cronbach's alpha was 0.94.

Conclusion

Our study provided evidence on the reliability and interpretation of the K6 score. Calculating the SDC of the K6 score can help identify the significance of changes in psychological distress over time and can determine the efficacy of interventions for psychological distress.

Long Working Hours, Precarious Employment and Anxiety Symptoms Among Working Chinese Population in Hong Kong

This study aimed to examine the association between working hours and anxiety of a working population in Hong Kong. We used a cross sectional data from a population-based household survey of Hong Kong Chinese adults. Key measures included employment status, skill level, working hours, length of stay at current job and anxiety level. Symptoms of anxiety were assessed using the Depression Anxiety Stress Scale (DASS-21). The data were analysed using logistic regression. Chinese adults who had long working hours (≥ 72 h per week) had higher odds of developing symptoms of anxiety than those who worked for ≤ 36 h per week (odds ratio [OR] 5.94, 95% confidence interval [CI]: 1.82‒19.41). Compared with short period (< 1 year), long period of stay at current job (≥ 5 years) was found as a protective factor from anxiety (OR 0.38, 95% CI: 0.20‒0.73). We found that a working period of 72 h per week was a significant threshold to cause anxiety to workers. Stable job arrangement was a protective factor to workers from anxiety. Implementation of labour market regulations, such as standard working hour policy and stable job arrangement, was also significant to mitigate risk of anxiety for working people in Hong Kong.