Validity and reliability of the Thai version of the work functioning impairment scale (Thai WFun)

Abstract

Background

In Thailand's agricultural sector, physically demanding labor and a high prevalence of chronic health conditions present substantial challenges to maintaining work capacity. However, few tools are available to assess work capacity among farmers.

Objective

This study aimed to evaluate the validity and reliability of the Thai version of the Work Functioning Impairment Scale (Thai WFun).

Methods

The study involved 385 rice farmers from Prakhon Chai district, Buriram province, Thailand, during November and December 2023. The WFun was translated from Japanese to Thai using a standard translation procedure. Participants then completed questionnaires, including the Thai WFun and the Work Ability Index (WAI). The convergent validity between the Thai WFun and WAI was examined through analysis of variance with linear trend tests. The factorial validity was assessed through confirmatory factor analysis (CFA) based on a one-factor model. The reliability of the Thai WFun was assessed using Cronbach's alpha.

Results

A significant linear trend was observed, indicating that as WAI scores decreased, Thai WFun scores increased (p < 0.001). Sub-factor analyses revealed similar patterns, including the physical and mental demands of work, a comparison with highest work ability ever, and absenteeism in the past year (all p < 0.001). CFA results demonstrated a reasonable model fit. The scale exhibited moderate internal consistency, with Cronbach's alpha of 0.668.

Conclusions

The findings validate the Thai WFun as a reliable tool for assessing work capacity among rice farmers, with potential to guide tailored occupational health strategies in agriculture.

Keywords

agriculture aging community health promotion occupational health presenteeism work capacity

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References

Arphorn

Manothum

Santiwung

, et al. Working conditions and urinalysis dipstick testing among female rice farmers: a preliminary cross-sectional study. Int J Environ Res Public Health 2021; 18: 8942.

Lursinsap

Sirisunyaluck

Sreshthaputra

, et al. Factors influencing the chance of inheriting the family farming career among heirs in the upper northern region of Thailand in the crisis of farming labor decline. Sustainability 2023; 15: 1709.

Arphorn

Lertvarayut

Kiatkitroj

, et al. Association between physical capacity and occupational falls among middle-aged and older farmers in Thailand: using the self-check risk assessment tool in Japan. J Occup Health 2021; 63: e12287.

Makishima

Fujino

Kubo

, et al. Validity and responsiveness of the work functioning impairment scale (WFun) in workers with pain due to musculoskeletal disorders. J Occup Health 2018; 60: 156–162.

Ishimaru

Fujino

Anzai

, et al. Validity and responsiveness of the work functioning impairment scale (WFun) in rheumatoid arthritis patients: a multicenter prospective study. Mod Rheumatol 2020; 30: 821–827.

Tabata

Yabe

Katogi

, et al. Investigation of presenteeism, physical function, and exercise habits in workers with CKD: three case reports with literature review. Renal Replace Ther 2022; 8: 16.

Yogyorn

Slatin

Siriruttanapruk

, et al. Estimating of the costs of nonfatal occupational injuries and illnesses in agricultural works in Thailand. J Public Health Policy 2021; 42: 71–85.

Kaewboonchoo

Ratanasiripong

. Psychometric properties of the Thai version of the work ability index (Thai WAI). J Occup Health 2015; 57: 371–377.

Nilvarangkul

Arphorn

Smith

, et al. Developing primary care occupational health services for informal sector workers in Thailand. Action Res 2015; 14: 113–131.

10.

Fujino

Uehara

Izumi

, et al. Development and validity of a work functioning impairment scale based on the rasch model among Japanese workers. J Occup Health 2015; 57: 521–531.

11.

Fujino

Liu

Chimed-Ochir

, et al. Cross-cultural validation of the work functioning impairment scale (WFun) among Japanese, English, and Chinese versions using Rasch analysis. J Occup Health 2019; 61: 464–470.

12.

Arphorn

Ishimaru

Lertvarayut

, et al. Risk factors for occupational falls among middle-aged and elderly farm workers in nan province, Thailand. J Agromed 2022; 27: 402–408.

13.

Sakai

Nagata

, et al. The new practice of interviews focusing on presenteeism provides additional opportunities to find occupational health issues. Environ Occup Health Pract 2022; 4: 2021-0021.

14.

Ishimaru

Mine

Fujino

. Two definitions of presenteeism: sickness presenteeism and impaired work function. Occup Med (Lond) 2020; 70: 95–100.

15.

Nagata

Fujino

Saito

, et al. Diagnostic accuracy of the work functioning impairment scale (WFun): a method to detect workers who have health problems affecting their work and to evaluate fitness for work. J Occup Environ Med 2017; 59: 557–562.

16.

Harkness

Schoua-Glusberg

. Questionnaires in translation, vol 3. Mannheim: ZUMA, Germany, 1998.

17.

El Fassi

Bocquet

Majery

, et al. Work ability assessment in a worker population: comparison and determinants of work ability Index and work ability score. BMC Public Health 2013; 13: 05.

18.

Bentler

. Cutoff criteria for fit indexes in covariance structure analysis: conventional criteria versus new alternatives. Struct Equation Model Multidiscip J 1999; 6: 1–55.

19.

Kopalle

Lehmann

. Alpha inflation? The impact of eliminating scale items on cronbach's alpha. Organ Behav Hum Decis Process 1997; 70: 189–197.

20.

Oakman

Neupane

Proper

, et al. Workplace interventions to improve work ability: a systematic review and meta-analysis of their effectiveness. Scand J Work Environ Health 2018; 44: 134–146.

21.

Fujino

Shazuki

Izumi

, et al. Prospective cohort study of work functioning impairment and subsequent absenteeism among Japanese workers. J Occup Environ Med 2016; 58: e264–e267.

22.

Ishimaru

Kubo

Honno

, et al. Near misses and presenteeism among paramedics. Occup Med (Lond) 2019; 69: 593–597.

23.

Michishita

Jiang

Ariyoshi

, et al. The Introduction of an active rest program by workplace units improved the workplace vigor and presenteeism among workers: a randomized controlled trial. J Occup Environ Med 2017; 59: 1140–1147.