Sex and race disparities in the association between work characteristics and vitamin D deficiency: findings from the National Health and Nutrition Examination Survey, 2005-2010.

OBJECTIVES: Vitamin D deficiency is highly prevalent worldwide; however, few large population-based studies have examined occupational risk factors. We examined associations between shift work, work schedule, hours worked, outdoor work, occupation and serum 25-hydroxyvitamin D (25(OH)D) levels in the US working population. METHODS: This cross-sectional study included 8601 workers from the 2005-2010 National Health and Nutrition Examination Survey (NHANES) cycles. NHANES occupational data were supplemented with measures of outdoor work from the Occupational Information Network. Serum 25(OH)D concentration in nanomoles per litre (nmol/L) was categorised as sufficient (≥75), insufficient (50-<75), moderately deficient (30-<50) and severely deficient (<30). Age-adjusted weighted multinomial and binary logistic regression were used to examine associations between work-related factors and vitamin D status with sex-race/ethnicity stratification. RESULTS: Shift workers had higher odds of severe vitamin D deficiency compared with day workers (OR: 1.64, 95% CI 1.22 to 2.19). Compared with those in white-collar occupations, those in natural resources were less likely to be deficient (OR: 0.31, 95% CI 0.19 to 0.52), while those in production were more likely to be deficient (OR: 2.25, 95% CI 1.48 to 3.43). Women working ≥40 hours/week compared with <40 hours/week were more likely to be moderately deficient (OR: 1.30, 95% CI 1.06 to 1.59). Black women working in sales were more likely to be deficient than those in management (OR: 1.53, 95% CI 1.03 to 2.27). Mexican American men working nights had the highest odds of deficiency (OR: 2.64, 95% CI 1.38 to 5.06). CONCLUSIONS: Work-related factors were associated with vitamin D status and there were race/ethnicity and sex differences. Targeted vitamin D screening and supplementation interventions may reduce these disparities.

Changes in work schedule affect headache frequency among Norwegian nurses: a 3-year-follow-up study.

OBJECTIVES: To explore whether changes in work schedule, number of night shifts and number of quick returns were related to changes in headache frequencies. METHODS: A longitudinal study with questionnaire data from 2014 (baseline) and 2017 (follow-up) on work schedule (day only, shift work without nights and shift work with nights), number of night shifts, number of quick returns (less than 11 hours in-between shifts) and validated headache diagnoses among 1104 Norwegian nurses. Associations were explored by adjusted multivariate regression analyses. RESULTS: The median age at baseline was 37 years (IQR 31-43) and 90.5% were women. In the adjusted logistic regression analysis of changed work schedule between baseline and follow-up, changing from night work was associated with increased odds for reversion from headache >1 days/month to no headache at all last year (OR 2.77 (1.29; 5.95)). Changes towards less night shifts (>10) or quick returns (>10) during the last year were associated with increased odds of reversion of headache to no headache (OR 2.23 (1.20; 4.17) and OR 1.90 (1.04; 3.49)). Only decrease in number of night shifts (>10) during the last year reduced risk of onset of any new headache between baseline and follow-up (OR of 0.39 (0.18; 0.84)). CONCLUSION: Changing from night work and reducing the number of night shifts and quick returns were associated with less headache in this 3-year-follow-up of Norwegian nurses. This adds to the growing body of evidence that night work may have direct negative health consequences.

The effect of shift work on body mass index: A systematic review and meta-analysis of observational studies.

CONTEXT: Shift work involves working outside the standard working hours of 9 am to 5 pm Monday to Friday and may include working evening, night, weekend, or rotating shift patterns. Since shift workers sleep less and their circadian rhythms are disrupted, they are reported to have higher body weight than day workers. OBJECTIVE: This meta-analysis aims to determine whether shift workers (SW) are more prone to higher body mass index (BMI) than their day workers (DW) counterparts. It also addresses the question of whether the duration of shift work exposure, sex, or occupational type affect BMI value. METHODS: Four databases that is PubMed, EBSCO Host, Scopus, and Web of Science were searched for reports published up to October 2023. RESULTS: Sixty-three studies involving a total of 693 449 participants met our inclusion criteria. Meta-analyses showed a significant effect of shift work on BMI value (standard mean difference; SMD: 0.10 kg/m2 [95% confidence interval; 95% CI: 0.07; 0.13; p < .001]) as compared with non-shift counterparts. Subgroup analysis revealed that shift work significantly increased BMI for studies where male working on this job schedule (SMD: 0.10 kg/m2 [95% CI: 0.04; 0.17; p = .0018]) for studies where shift workers worked ≥13 years (calculated as the median of shift work experience; SMD: 0.14 kg/m2 [95% CI: 0.10; 0.18; p < .001]) as well as for studies where industrial (SMD: 0.12 kg/m2 [95% CI: 0.05; 0.19; p = .0012]) and other type of occupations were dominated (0.12 kg/m2 [95% CI: 0.07; 0.16; p < .001]). CONCLUSIONS: We found that in general working on a shift schedule increases BMI as compared with day workers, especially in case of male employed in this job schedule, for shift workers working for long periods of time (≥13 years), and for shift workers employed in industry and other type of occupations(e.g., airline workers, firefighters, police officers, blue collar, security personnel, bus drivers, garbage collectors, railway workers, postal, oil and gas workers).

The Effect of Shift Working on Dietary Patterns of Healthcare Practitioners during the COVID-19 Pandemic: A Cross-Sectional Study.

Background and Objectives: Health professionals' working schedules often do not allow them to follow a balanced way of life, and the nature of their work can affect their weight and eating habits. The aim of the present study is to shed some light on the impact of night shift working on the dietary practices of healthcare practitioners in Greece. Materials and Methods: This was a cross-sectional study. With the use of an administered questionnaire several parameters were assessed, including anthropometric characteristics, weight history, as well as nutritional habits of the same group of participants during night shifts and when at regular working hours. Moreover, nutritional beliefs of the subjects were recorded, as well as the level of adherence to the Mediterranean diet. Results: It was observed that in all food groups, including water, used to compare the nutritional patterns of the participants during night shifts and when working regular hours, statistical differences were noted (p = 0.001). Furthermore, the participants who reported a higher adherence to the Mediterranean diet and self-reported healthier nutritional habits, had a statistically lower weight compared to the participants that rarely followed the specific model or reported unhealthier eating routine (p = 0.010 and p = 0.015, respectively). Conclusions: We conclude that shift-working healthcare professionals are associated with disturbed eating behaviours leading to the high consumption of unhealthy food. The implementation of interventions that will concentrate on educating health workers on balanced nutrition and improving physical environment (i.e., food availability, healthier food choices) seems to be of great importance.

Past Shift Work and Incident Coronary Heart Disease in Retired Workers: A Prospective Cohort Study.

Present shift work has been associated with coronary heart disease (CHD) among employed workers, but it remains unclear whether shift work performed in the past is still associated with CHD in retired workers. We recruited 21,802 retired workers in Shiyan, China, in 2008-2010 and 2013 and followed them for CHD events occurring up to December 31, 2018. Retired workers with longer durations of past shift work (rounded to 0.25 years) had higher CHD risks (for those with ≤5.00, 5.25-10.00, 10.50-20.00, and >20.00 years of past shift work, hazard ratios were 1.05 (95% confidence interval (CI): 0.94, 1.16), 1.08 (95% CI: 0.94, 1.25), 1.23 (95% CI: 1.07, 1.42), and 1.28 (95% CI: 1.08, 1.51), respectively). The association was substantially higher among service or sales workers than among manufacturing or manual-labor workers (for every 5-year increase in past shift work, hazard ratio = 1.11 (95% CI: 1.05, 1.16) vs. hazard ratio = 1.02 (95% CI: 0.98, 1.06)). Moreover, the risk was lower among those who were physically active than among their inactive counterparts (P for interaction = 0.019). Longer duration of past shift work was associated with higher risk of incident CHD among these retired workers, especially those from the service or sales sectors. Physical exercise might be beneficial in reducing the excess risk.

Factors Associated with Emergency Department Length of Stay in Critically Ill Patients: A Single-Center Retrospective Study.

BACKGROUND Length of stay (LOS) in the emergency department (ED) should be measured and evaluated comprehensively as an important indicator of hospital emergency service. In this study, we aimed to analyze clinical characteristics of critically ill patients admitted to the ED and identify the factors associated with LOS. MATERIAL AND METHODS All patients with level 1 and level 2 of the Emergency Severity Index who were admitted to the ED from January 2018 to December 2019 were included in this retrospective study. The patients were divided into 2 groups: LOS ≥4 h and LOS <4 h. Variables were comprehensively analyzed and compared between the 2 groups. RESULTS A total of 19 616 patients, including 7269 patients in the LOS ≥4 h group and 12 347 patients in the LOS <4 group, were included. Advanced age, admission in winter and during the night shift, and diseases excluding nervous system diseases, cardiovascular diseases, and trauma were associated with higher risk of LOS. Nervous system diseases, cardiovascular diseases, trauma, and procedures including tracheal intubation, surgery, percutaneous coronary intervention, and thrombolysis were associated with lower risk of LOS. CONCLUSIONS Prolonged LOS in the ED was associated with increased age and admission in winter and during the night shift, while shortened LOS was associated with nervous system diseases, cardiovascular diseases, and trauma, as well as with procedures including tracheal intubation, surgery, percutaneous coronary intervention, and thrombolysis. Our findings can serve as a guide for ED physicians to individually evaluate patient condition and allocate medical resources more effectively.

Nightly fasting duration is not associated with the prevalence of metabolic syndrome among non-shift workers: The Furukawa Nutrition and Health Studymx.

OBJECTIVES: While several experimental studies in animals and humans have suggested the protective effect of nightly fasting duration (NFD) against cardiometabolic risk factors, few population-based studies have been conducted. This study aimed to investigate the association between NFD and metabolic syndrome (MetS) among Japanese non-shift workers. METHODS: A subset of 1054 non-shift workers from the Furukawa Nutrition and Health Study were included in this analysis. Participants completed dietary and lifestyle surveys during a periodic checkup. NFD was defined as the time between dinner and breakfast and was categorized into four groups (ie, ≥12 hours, 11 hours, 10 hours, and ≤9 hours). MetS was defined as ≥3 of the following components: high waist circumference (≥90 cm [men] and ≥80 cm [women]), high triglycerides (≥150 mg/dL), low high-density lipoprotein cholesterol (<40 mg/dL [men] and <50 mg/dL [women]), hypertension (systolic blood pressure ≥130 mm Hg or diastolic blood pressure ≥85 mm Hg), and high fasting glucose (fasting plasma glucose ≥100 mg/dL or hemoglobin A1c ≥5.6%). A multivariable logistic regression model was used to examine the association between NFD and MetS. RESULTS: The odds ratios (95% confidence intervals) of MetS for the highest (≥12 hours) through lowest (≤9 hours) NFD categories were 1.00 (reference), 0.83 (0.51-1.35), 0.83 (0.48-1.43), and 0.80 (0.43-1.48) (P for trend = 0.50) after adjusting for covariates. Further analyses on the relationship between NFD and each MetS component found no significant associations. CONCLUSIONS: We did not find any evidence of a significant association between NFD and MetS among non-shift workers in Japan.

Pediatric Residents' Perception of Medical Education, General Wellness and Patient Care Following the Shortening of Shifts during the COVID-19 Pandemic.

BACKGROUND: The effect of extended shift length on pediatric residency is controversial. Israeli residents perform shifts extending up to 26 hours, a practice leading to general dissatisfaction. In early 2020, during the coronavirus disease-2019 (COVID-19) pandemic, many Israeli hospitals transitioned from 26-hour shifts to 13-hour shifts in fixed teams (capsules) followed by a 24-hour rest period at home. The regulation changes enacted by the Israeli government during the COVID-19 pandemic provided a rare opportunity to assess perception by residents regarding length of shifts before and after the change. OBJECTIVES: To assess perception of pediatric residency in three aspects: resident wellness, ability to deliver quality healthcare, and acquisition of medical education following the change to the shorter shifts model. METHODS: We performed a prospective observational study among pediatric residents. Residents completed an online self-assessment questionnaire before and after the COVID-19 emergency regulations changed toward shorter shifts. RESULTS: Sixty-seven residents answered the questionnaires before (37) and after (30) the shift changes. The average score was significantly better for the 13-hour shifts versus the 26-hour shifts, except for questions regarding available time for research. There was a positive perception regarding the shorter night shifts model among pediatric residents, with an increase in general satisfaction and improvement in perception of general wellness, ability to deliver quality healthcare, and medical education acquisition. CONCLUSIONS: Following the change to shorter shift length, perception of pediatric residents included improvement in wellness, ability to deliver quality healthcare, and availability of medical education.

Rituals, ghosts and glorified babysitters: A narrative analysis of stories nurses shared about working the night shift.

Working the night shift can be fraught and experienced as demanding and, yet, is often dismissed as babysitting. Few researchers have explored the social and cultural meanings of night nursing, including storytelling rituals. In 2019, a narrative study was undertaken. The aim was to explore the stories recalled by nurses about working night shifts. Thirteen Australian nurses participated. Data were gathered using the Biographical Narrative Interview Method, and narrative analysis produced forty stories and three themes: strange and challenging experiences; colleagues can be mentors (or not); and textbook knowledge is only part of what is needed on night shift. Nursing students who engage with these stories may come to understand the challenges of the night shift, and the valuable work that nurses engage in throughout a 24-hr period, work that involves adept psychosocial and interpersonal skills alongside technical and physical competence.

Short sleep duration and high exposure to quick returns are associated with impaired everyday memory in shift workers.

PURPOSE: To investigate the relationship between self-reported everyday memory problems the last month, and: (a) shift work schedule, (b) night shifts and quick returns worked the last year, and (c) sleep duration the last month. METHODS: In all, 1,275 nurses completed the Everyday Memory Questionnaire - revised, and answered questions about shift work exposure and sleep duration. We performed multiple linear regression analyses with memory score as dependent variable, and the shift work exposure variables as well as sleep duration as predictors, while adjusting for potential confounders. FINDINGS: High exposure to quick returns (ß = .10, p < .05) and short sleep duration (ß = .10, p < .05) were both positively associated with memory problems, whereas shift work schedule, long sleep duration, night shift exposure, and low and moderate exposure to quick returns were not. DISCUSSION: Frequent insufficient time for rest between shifts as well as short sleep was associated with poorer everyday memory.

Circadian genes polymorphisms, night work and prostate cancer risk: Findings from the EPICAP study.

Over the past two decades, several studies have attempted to understand the hypothesis that disrupting the circadian rhythm may promote the development of cancer. Some have suggested that night work and some circadian genes polymorphisms are associated with cancer, including prostate cancer. Our study aims to test the hypothesis that prostate cancer risk among night workers may be modulated by genetic polymorphisms in the circadian pathway genes based on data from the EPICAP study, a population-based case-control study including 1511 men (732 cases/779 controls) with genotyped data. We estimated odds ratio (ORs) and P values of the association between prostate cancer and circadian gene variants using logistic regression models. We tested the interaction between circadian genes variants and night work indicators that were significantly associated with prostate cancer at pathway, gene and SNP levels. Analyses were also stratified by each of these night work indicators and by cancer aggressiveness. The circadian pathway was significantly associated with aggressive prostate cancer among night workers (P = .004), particularly for men who worked at night for <20 years (P = .0002) and those who performed long night shift (>10 hours, P = .001). At the gene level, we observed among night workers significant associations between aggressive prostate cancer and ARNTL, NPAS2 and RORA. At the SNP-level, no significant association was observed. Our findings provide some clues of a potential modulating effect of circadian genes in the relationship between night work and prostate cancer. Further investigation is warranted to confirm these findings and to better elucidate the biological pathways involved.

Disruption of central and peripheral circadian clocks in police officers working at night.

Working atypical schedules leads to temporal misalignments between a worker's rest-activity cycle and their endogenous circadian system. Several studies have reported disturbed centrally controlled rhythms, but little is known on shift workers' peripheral clocks. Here, we assessed central clock markers, urinary 6-sulfatoxymelatonin and salivary cortisol, and clock gene expression in 2 peripheral clocks, oral mucosa cells and peripheral blood mononuclear cells (PBMCs), in 11 police officers. Before working 7 consecutive nights, officers' centrally controlled rhythms were aligned to a day-oriented schedule. These rhythms were partially realigned to the shifted schedule and dampened after a week working nights. For peripheral clocks at baseline, Period (PER)1-3 and nuclear receptor subfamily 1, group D, member 1 (REV-ERBα) in oral mucosa cells had a significant mRNA peak in the afternoon, whereas in PBMCs, higher PER1-3 expression was observed at 10:00 compared with 19:30. After a week working nights, PER1-3 and REV-ERBα expression in oral mucosa cells lost rhythmicity, and in PBMCs, the morning/evening difference observed at baseline was lost. To our knowledge, this is the first study to demonstrate the disruption of several peripheral clocks in real shift workers. Molecular circadian disturbances are believed to have important clinical implications for the occurrence of shift work-associated medical disorders.-Koshy, A., Cuesta, M., Boudreau, P., Cermakian, N., Boivin, D. B. Disruption of central and peripheral circadian clocks in police officers working at night.

Mental Health Consequences of Shift Work: An Updated Review.

PURPOSE OF REVIEW: Approximately 25% of employed individuals engage in shift work, which can substantially alter opportunities for restorative sleep. Being tired on the job can lead to safety risks in professions such as healthcare, first responders, manufacturing, and numerous others. In addition to the physical stress and health consequences of shift work, recent evidence links shift work to poor mental health outcomes. The current review examines the literature from 2016 onward, emphasizing the impact of shift work on mental health. RECENT FINDINGS: Shift work is associated with considerable impacts on sleep, depressed mood and anxiety, substance use, impairments in cognition, lower quality of life, and even suicidal ideation. Pronounced sleep disturbances frequently underlie the mental health consequences of shift work. Shift work can have physical, mental health, and safety consequences. Future research should aim to better understand the interplay of shift work, sleep, and mental health and seek to mitigate the adverse consequences of shift work.

No association between night shiftwork and mammographic density.

BACKGROUND: Increased mammographic density is one of the strongest risk factors for breast cancer. Night shiftwork and its related factors, which include light at night, phase shift and sleep disruption, are believed to increase breast cancer risk however, their effects on mammographic density have barely been studied. METHODS: This study included 1821 women enrolled in the Breast Cancer Environment and Employment Study between 2009 and 2011. Mammographic density was measured using the Cumulus software program. The association of night shiftwork factors with square root transformed absolute dense area (DA) and percentage dense area (PDA) were modelled using linear regression adjusted for confounders. RESULTS: Ever doing graveyard shiftwork (between 24:00 and 05:00 hours) was not associated with PDA (ß=-0.10; 95% CI -0.27 to 0.08)) and DA (ß=-0.12; 95% CI -0.33 to 0.09)). No association was found between night shiftwork related factors (light at night, phase shift and sleep disturbance) with PDA or DA. CONCLUSIONS: Shiftwork and its related factors are not associated with mammographic density. Using high-quality, comprehensive shiftwork data from a large population-based breast cancer case-control study, this study suggests that mammographic density does not play a role in the relationship between shiftwork and breast cancer risk.

Monthly fluctuations in 25-hydroxy-vitamin D levels in day and rotating night shift hospital workers.

PURPOSE: Epidemiological studies have suggested that indoor hospital employees, either day or night shift workers, are at high risk of metabolic and cardiovascular diseases. Interestingly, previous reports have also described a higher prevalence of vitamin D (25OHD) deficiency among these workers. However, few studies have determined the monthly variations in 25OHD levels in indoor hospital employees. METHODS: To address this lack of knowledge, in 2018, during the periodic health surveillance checks at the Service of Occupational Medicine, we measured 25OHD levels in a group of indoor hospital workers (88 rotating night shift workers vs 200 day workers). Each participant received a single annual health surveillance check. RESULTS: The mean levels of 25OHD were consistently below the lower limit of the normal range in both groups throughout the year. Only in the summer, day workers but not rotating night shift workers (mean 25.9 ± 11.3 ng/ml vs 23.1 ± 9.1 ng/ml; p = 0.042) showed levels significantly higher than those in the other seasons. This difference remained statistically significant even after correction for study covariates [ß = -  1.649 (CI - 0.283/- 3.482), p = 0.039]. A cosinor analysis confirmed that the difference in the 25OHD levels between groups was present later in the year. CONCLUSIONS: We found that relatively young healthy hospital workers, especially those with rotating night shifts, in the absence of significant metabolic risk factors, have a high risk of 25OHD deficiency/insufficiency. Because 25OHD deficiency may lead to a progression to more severe conditions such as osteoporosis or bone fractures, our results should be verified in larger cohorts including different ancestries.

Gender differences and occupational factors for the risk of obesity in the Italian working population.

BACKGROUND: Obesity is a multifactorial condition and a major risk factor associated with several non-communicable diseases, such as cardiovascular disease, and with a higher risk of premature death and disability. Sex-specific factors have key roles and must be taken into consideration in studying occupational factors associated with the risk of obesity. The aim of this study was to investigate gender differences in body mass index (BMI) in a large cohort representative of Italian workers and, correlating this index with several demographic and occupational variables, to verify sex- and work-dependent differences in the risk of obesity. METHODS: We utilized data from INSuLa, a cross-sectional, nationally representative survey of the Italian worker population conducted in 2013 by the Italian Workers' Compensation Authority to investigate health and safety at work. Analyses were run on a sample of 8000 Italian workers, aged from 16 to 64 years. Logistic regression models were employed to assess gender differences in the relation between occupational characteristics and BMI. We adjusted for age, education, variables related to health protection at work, and chronic conditions and diseases. RESULTS: There were several significant differences in the BMI between males and females, linked to some occupational factors. For instance, female shift workers were 1.32 times (95% CI 1.11-1.57) more likely to be overweight or obese than normal-weight workers, and this association was maintained when controlling for confounders. The likelihood of overweight or obesity among women who worked 1-2 night shifts per week was significantly higher - 1.5-1.6 times - than those on day shifts. CONCLUSIONS: Gender-specific differences in occupational factors associated with the risk of obesity are useful with a view to characterizing this risk and helping identify workplace-targeted intervention strategies.

The relationship between the pattern of shift work and sleep disturbances in Korean firefighters.

PURPOSE: Sleep disturbances are prevalent in firefighters, but the relationship between patterns of shift work and sleep disturbances has not yet been investigated. Here, this relationship has been evaluated in Korean firefighters. METHODS: A cross-sectional study was conducted using an online questionnaire, which captured demographic, psychosocial and work-related characteristics. Sleep disturbance was assessed using the insomnia severity index (ISI). The relationship between insomnia and work-related factors (including type of shift work and the frequency of emergency events and off-duty work which means overtime work on off days) was analyzed. RESULTS: A total of 9810 firefighters completed the survey, representing approximately 21.5% of all Korean firefighters; data from 9738 subjects were included in the analysis. All firefighter roles were significantly associated with insomnia; the odds ratio (OR) was 2.456 (95% confidence interval [CI] 1.461-4.128) for fire suppression and 1.871 (95% CI 1.105-3.167) for the emergency medical services and rescue. However, the pattern of shift work did not show a statistically significant relationship. The OR increased along with the frequency of emergency events and off-duty work (p value for trend < 0.05). CONCLUSIONS: This study found a significant association between the frequency of emergency and off-duty work and insomnia in Korean firefighters, whereas the pattern of shift work showed no significant relationship. Therefore, measures to reduce the frequency of emergency and off-duty work are required to prevent sleep disturbances in firefighters.

Pain complaints are associated with quick returns and insomnia among Norwegian nurses, but do not differ between shift workers and day only workers.

PURPOSE: To determine whether common work schedule characteristics among Norwegian nurses were associated with subjective pain complaints. METHODS: A cross-sectional study in a sample of 1585 nurses, part of the longitudinal questionnaire-based cohort project 'Survey of Shift work, Sleep and Health' (SUSSH). Pain from six regions were assessed: 'headache', 'neck/shoulder/upper back', 'upper extremities', 'lower back', 'lower extremities', and 'abdomen'. Logistic and negative binomial regression (adjusted for age, sex, percentage of full-time equivalent, marital status and children living at home) were conducted where work schedule, number of night shifts last year, number of quick returns (QR) last year (< 11 h between shifts) and insomnia were predictors of localized pain, widespread pain and number of pain sites. RESULTS: Localized pain, widespread pain and number of pain sites were associated with insomnia (OR 2.06, 95% CI 1.66-2.55, OR 2.14, 95% CI 1.47-3.09, IRR 1.70, 95% CI 1.51-1.91, respectively). Work schedule and number of night shifts worked last year were not associated with any of the three pain measures. Number of QRs worked last year tended to be associated with number of pain sites. CONCLUSION: The study did not support the hypothesis that non-daytime work schedules are associated with pain complaints. Neither was there support for the hypothesis linking number of night shifts, or the number of QRs, to pain complaints. Future studies should aim to determine the association between QRs and pain in more detail. Pain complaints were associated with insomnia.

Development and psychometric evaluation of the women shift workers' reproductive health questionnaire: a sequential exploratory mixed-method study.

BACKGROUND: There is no standard and comprehensive questionnaire for reproductive health assessment among women shift workers. This study aimed at the development and psychometric evaluation of the Women Shift Workers' Reproductive Health Questionnaire. METHODS: This sequential exploratory mixed-method study was conducted in a qualitative (item generation) and a quantitative (psychometric evaluation) phase. In the qualitative phase, the primary item pool of the questionnaire was generated based on the findings of the qualitative content analysis of 21 interviews held with 21 women shift workers as well as the findings of a literature review. In the quantitative phase, the face, content, construct, convergent, and discriminant validity and the reliability of the questionnaire were assessed. For construct validity assessment through exploratory and confirmatory factor analyses, 620 women shift workers were conveniently selected to fill out the questionnaire. Reliability assessment was done through assessing internal consistency, stability, and composite reliability. RESULTS: The primary item pool contained 88 items. During face and content validity, item number was reduced to 55. Construct validity assessment through factor analysis revealed that 56.50% of the total variance was explained by five factors with 34 items. The factors were named motherhood, general health, sexual relationships, menstruation, and delivery. Confirmatory factor analysis confirmed the fit of the five-factor model. The Cronbach's alpha and the composite reliability value of the questionnaire were more than 0.7. CONCLUSION: The Women Shift Workers' Reproductive Health Questionnaire is a valid and reliable instrument and can be used for reproductive health assessment among women shift workers.