Morten Birkeland Nielsen1, Stein Knardahl2. 1. National Institute of Occupational Health, Pb 8149 Dep, 0033, Oslo, Norway. morten.nielsen@stami.no. 2. National Institute of Occupational Health, Pb 8149 Dep, 0033, Oslo, Norway. stein.knardahl@stami.no.
Abstract
PURPOSE: To determine the impact of the healthy worker effect (HWE) as a bias for the external and internal validity of the follow-up assessment in prospective survey research. Specifically, the study examined (1) whether the health status of respondents at the baseline measurement influenced response at the follow-up survey (external validity) and (2) whether HWE is a threat to internal validity by differential attrition, i.e., whether associations between work and health at baseline differ between stayers and dropouts. METHODS: In a two-wave questionnaire survey with a 2-year time lag comprising 6283 persons, 4392 responded at both time points (response rate 70%). Mental distress and somatic symptoms served as indicators of health. Role conflict and role clarity were indicators of work factors. RESULTS: There were few differences in response rate at follow-up between persons with and without health complaints at the baseline measurement. As response rate increased incrementally with educational level, there seems to be a socio-educational bias, rather than a HWE bias on survey participation. Baseline relationships between work factors and health indicators were equal in magnitude among stayers and dropouts. CONCLUSION: The health status of participants at baseline seems to have little impact on the external and internal validity of the follow-up assessment in prospective survey research. Hence, the findings provide little support to the HWE as a potential bias in prospective studies within occupational health research. A limitation of the study is that the findings do not inform about the impact of the HWE on participation in the baseline assessment.
PURPOSE: To determine the impact of the healthy worker effect (HWE) as a bias for the external and internal validity of the follow-up assessment in prospective survey research. Specifically, the study examined (1) whether the health status of respondents at the baseline measurement influenced response at the follow-up survey (external validity) and (2) whether HWE is a threat to internal validity by differential attrition, i.e., whether associations between work and health at baseline differ between stayers and dropouts. METHODS: In a two-wave questionnaire survey with a 2-year time lag comprising 6283 persons, 4392 responded at both time points (response rate 70%). Mental distress and somatic symptoms served as indicators of health. Role conflict and role clarity were indicators of work factors. RESULTS: There were few differences in response rate at follow-up between persons with and without health complaints at the baseline measurement. As response rate increased incrementally with educational level, there seems to be a socio-educational bias, rather than a HWE bias on survey participation. Baseline relationships between work factors and health indicators were equal in magnitude among stayers and dropouts. CONCLUSION: The health status of participants at baseline seems to have little impact on the external and internal validity of the follow-up assessment in prospective survey research. Hence, the findings provide little support to the HWE as a potential bias in prospective studies within occupational health research. A limitation of the study is that the findings do not inform about the impact of the HWE on participation in the baseline assessment.
Entities:
Keywords:
Attrition; Generalizability; Non-response bias; Participation; Research design
Authors: D A Powell; E Furchtgott; M Henderson; L Prescott; A Mitchell; P Hartis; J D Valentine; W L Milligan Journal: Exp Aging Res Date: 1990 Spring-Summer Impact factor: 1.645
Authors: P Nettelbladt; L Hansson; C G Stefansson; L Borgquist; G Nordström Journal: Soc Psychiatry Psychiatr Epidemiol Date: 1993-07 Impact factor: 4.328
Authors: Karina Glies Vincents Seeberg; Sebastian Venge Skovlund; Rúni Bláfoss; Kristina Thomassen; Lasse Malchow-Møller; Emil Sundstrup; Lars Louis Andersen Journal: Int J Environ Res Public Health Date: 2022-04-20 Impact factor: 4.614