Are lifestyle pattern changes associated to poor subjective sleep quality?: a cross-sectional study by gender among the general Japanese population underwent specified medical check-ups in 2014 and 2015

Association of low back pain and sleep quality with presenteeism

BACKGROUND

Low back pain (LBP) and poor subjective sleep quality (SSQ) are major risk factors for presenteeism. However, no studies have investigated whether combined LBP and poor SSQ are associated with presenteeism.

AIMS

We aimed to examine whether a combination of LBP and poor SSQ is associated with presenteeism.

METHODS

This cross-sectional study included 936 workers (median age, 38 years; men, 89%), with evaluated presenteeism using the work limitations questionnaire. We divided them into 'no presenteeism' and 'presenteeism' categories. The presence of LBP was defined as a numerical rating scale (NRS) score of ≥1 in current pain intensity. SSQ was assessed using a single question regarding whether the participants typically got enough sleep. We categorized the participants into four groups: (i) LBP + poor SSQ, (ii) non-LBP + poor SSQ, (iii) LBP + good SSQ and (iv) non-LBP + good SSQ. Logistic regression analysis was used to investigate the association between presenteeism and the presence of LBP and poor SSQ, adjusting for age, sex, work type, education, marital status, smoking status, body mass index and weekly working hours.

RESULTS

The data from 533 participants were used for analysis (median age, 38 years; men, 90%, response rate, 66%). Combined LBP and poor SSQ were significantly associated with presenteeism (non-LBP + poor SSQ: adjusted odds ratio = 0.56, 95% CI 0.32-0.96; LBP + good SSQ: 0.33, 0.20-0.56; non-LBP + good SSQ: 0.29, 0.18-0.48).

CONCLUSIONS

Evaluating both LBP and SSQ may be beneficial in considering presenteeism.

Statistical Methods for Item Reduction in a Representative Lifestyle Questionnaire: Pilot Questionnaire Study

Background

Reducing the number of items in a questionnaire while maintaining relevant information is important as it is associated with advantages such as higher respondent engagement and reduced response error. However, in health care, after the original design, an a posteriori check of the included items in a questionnaire is often overlooked or considered to be of minor importance. When conducted, this is often based on a single selected method. We argue that before finalizing any lifestyle questionnaire, a posteriori validation should always be conducted using multiple approaches to ensure the robustness of the results.

Objective

The objectives of this study are to compare the results of two statistical methods for item reduction (variance inflation factor [VIF] and factor analysis [FA]) in a lifestyle questionnaire constructed by combining items from different sources and analyze the different results obtained from the 2 methods and the conclusions that can be made about the original items.

Methods

Data were collected from 79 participants (heterogeneous in age and sex) with a high risk of metabolic syndrome working in a financial company based in Tokyo. The lifestyle questionnaire was constructed by combining items (asked with daily, weekly, and monthly frequency) from multiple validated questionnaires and other selected questions. Item reduction was conducted using VIF and exploratory FA. Adequacy tests were used to check the data distribution and sampling adequacy.

Results

Among the daily and weekly questions, both VIF and FA identified redundancies in sleep-related items. Among the monthly questions, both approaches identified redundancies in stress-related items. However, the number of items suggested for reduction often differed: VIF suggested larger reductions than FA for daily questions but fewer reductions for weekly questions. Adequacy tests always confirmed that the structural detection was adequate for the considered items.

Conclusions

As expected, our analyses showed that VIF and FA produced both similar and different findings, suggesting that questionnaire designers should consider using multiple methods for item reduction. Our findings using both methods indicate that many questions, especially those related to sleep, are redundant, indicating that the considered lifestyle questionnaire can be shortened.