Evaluating validity of MODAPTS as an assessment method of work speed in relation to the open labour market

Abstract

Background: Based on latest statistics only 0.9% of the Economically Active People in South Africa are persons with disabilities. Furthermore, many of the persons with disability in South Africa are employed in sheltered employment with little or no prospect of career advancement. The White Paper on the Rights of Persons with Disabilities (WPRPD) thus identifies the need for removing discriminatory barriers that hinder equal participation of people with disabilities. Occupational therapists (OTs) are uniquely qualified to evaluate and treat occupational dysfunction that hinders participation in gainful employment and to advocate for the rights of persons with disability in the workplace. OTs depend on standardised procedures to evaluate work capacity and to determine ability to work and rehabilitation needs. It is of importance that valid and reliable test results be obtained to inform these decisions. At present, it appears that expensive and imported assessment methods are used. MODAPTS could prove to be a more cost-effective alternative to standardise work assessments, yet hardly any studies report its validity as an assessment method in OT. This study aimed to evaluate face, content and criterion validity of MODAPTS as an assessment method of work speed.

Methods: A quantitative cross-sectional research design was used. Two electronic surveys were utilised to determine face and content validity of MODAPTS. The Lynn method was used to analyse data related to face and content validity. Criterion validity was evaluated by comparing MODAPTS to the gold standard of work samples, namely Valpar Component Work Samples (VCWS) that utilises the Methods-Time-Measurement (MTM) technique. The specific VWCS used to compare with MTM and MODAPTS times was informed by a realist synthesis that focused on the content of work assessments. VCWS 9, VCWS 4 and VCWS 6 was used. A deterministic model was used to evaluate the comparability of MODAPTS to MTM.

Results: Face validity for MODAPTS as an assessment method of work speed was confirmed through an agreement of 94.73% (>80% demonstrates adequate agreement). Content validity for the codes used to analyse basic movement and handling of smaller and larger articles as well as other body actions was confirmed with an agreement of 100% respectively. Content validity for mental and clerical operations codes was not confirmed with an agreement of 67% respectively. Criterion validity for tasks involving basic movements, handling smaller articles and other body actions was confirmed. Criterion validity for tasks involving mental and clerical operations was not confirmed. The results of the content and criterion validity are consistent.

Conclusion: MODAPTS demonstrated adequate face validity. Content and criterion validity of tasks involving basic movements, handling of articles and other body actions was confirmed. However, content and criterion validity for tasks involving mental and clerical operations was not confirmed. The results of this study indicate that MODAPTS can be used to assess work speed in physical and manual tasks.