Cross-cultural adaptation of the work role functioning questionnaire to Korean

Abstract

Objective

Work Role Functioning Questionnaire(WRFQ) is widely used in measuring outcomes of work rehabilitation interventions and in evaluating return to work programs for workers with physical impairments. The objectives of this study are to translate, and to conduct the cross-cultural adaptation of the WRFQ to Korean and to assess its usability in Korean health care service field.

Methods

Translation was carried out according to systematized standards for the cultural adaptation of instruments used in the occupational health field: (1)forward translation, (2)synthesis, (3)backward translation, (4)consolidation of translations by a committee of experts. And then, it was administered to fifty volunteer workers of both sexes, with physical(musculoskeletal) and/or mental(anxiety and/or depression) health problems with a minimum duration of 4 weeks. They were recruited when they visited an in-company clinic with the purpose of medical check up. Investigation of musculoskeletal and mental disorders was also performed at the same time. NIOSH symptom criteria for musculoskeletal disorders(Korean version, KOSHACODE H-30-2003) and CES-D(Center for Epidemiological Studies- Depression Scale), BAI(Beck Anxiety Inventory) were used. To evaluate the internal consistency, the Cronbach''s alpha coefficient was calculated for each subscale of the questionnaires. The repeatability or stability of the instrument was assessed through test-retest reliability with a sufficient gap of time(at least 2 weeks). Finally, construct validity was evaluated comparing the median values of the subscale scores between physical and mental disorder groups.

Result

The study sample was composed of 36 men and 14 women, with a mean age of 32.5 years. Workers in their twenties were the highest(46.0%) and majority of job type was manual(80.0%). The Cronbach’s alpha coefficient was 0.92 in the total scale, above 0.70 in all subscales. The Intraclass Correlation Coefficients(ICC) for the test-retest reliability were ranged between 0.83(95% CI: 0.72-0.90, Physical demands) and 0.94(95% CI: 0.89-0.94, Flexibility demands). The ICC for the total score was 0.90(95% CI: 0.83-0.94). Construct validity was considered proper. The difference of physical demands scores between the two groups(low and high) were statistically significant(p<0.05). On the other hand, the state of mental disorders strongly influences on overall subscales except physical demands.

Conclusion

The cross-cultural adaptation of the WRFQ was successful without major problems. The Korean version of the WRFQ(WRFQ-K) demonstrated excellent acceptability and psychometric properties. This study also proved its usefulness in terms of validity and reliability. We believe that our study can help researchers and clinicians to measure outcomes of work rehabilitation interventions and to evaluate return to work programs for workers with impairment.