NIPSA: a new scale for measuring non-illness predictors of sickness absence

We describe the development and initial validation of a new scale for measuring non-illness factors that are important in predicting occupational outcomes, called the NIPSA (non-illness predictors of sickness absence) scale.

Forty-two questions were developed which covered a broad range of potential non-illness-related risk factors for sickness absence. 682 participants in the South East London Community Health study answered these questions and a range of questions regarding both short-term and long-term sickness absence. Factor analysis was conducted prior to examining the links between each identified factor and sickness absence outcomes.

Exploratory factor analysis using the oblique rotation method suggested the questionnaire should contain 26 questions and extracted four factors with eigenvalues greater than 1: perception of psychosocial work environment (factor 1), perceived vulnerability (factor 2), rest-focused attitude towards recovery (factor 3) and attitudes towards work (factor 4). Three of these factors (factors 1, 2 and 3) showed significant associations with long-term sickness absence measures (p<0.05), meaning a final questionnaire that included 20 questions with three subscales.

The NIPSA is a new tool that will hopefully allow clinicians to quickly assess for the presence of non-illness factors that may be important in predicting occupational outcomes and tailor treatments and interventions to address the barriers identified. To the best of our knowledge, this is the first time that a scale focused on transdiagnostic, non-illness-related predictors of sickness absence has been developed.