Proof‐of‐concept of a data‐driven approach to estimate the associations of comorbid mental and physical disorders with global health‐related disability
Abstract
Objective: The standard method of generating disorder‐specific disability scores has
lay raters make rankings between pairs of disorders based on brief disorder vignettes. This method introduces bias due to differential rater knowledge of disorders and inability to disentangle the disability due to disorders from the disability
due to comorbidities.
Methods: We propose an alternative, data‐driven, method of generating disorder‐
specific disability scores that assesses disorders in a sample of individuals either
from population medical registry data or population survey self‐reports and uses
Generalized Random Forests (GRF) to predict global (rather than disorder‐specific)
disability assessed by clinician ratings or by survey respondent self‐reports. This
method also provides a principled basis for studying patterns and predictors of
heterogeneity in disorder‐specific disability. We illustrate this method by analyzing
data for 16 disorders assessed in the World Mental Health Surveys (n = 53,645).
Results: Adjustments for comorbidity decreased estimates of disorder‐specific
disability substantially. Estimates were generally somewhat higher with GRF than
conventional multivariable regression models. Heterogeneity was nonsignificant.
Conclusions: The results show clearly that the proposed approach is practical, and
that adjustment is needed for comorbidities to obtain accurate estimates of
disorder‐specific disability. Expansion to a wider range of disorders would likely find
more evidence for heterogeneity
Reference: International Journal of Methods in Psychiatric Research, 33(1), e2003. https://doi.org/10.1002/mpr.2003
Keywords: causal forest, comorbidity, disability, global burden of disease, mental disorders