Rationale
Health-related productivity loss and the impact of comorbidities on the economic burden of asthma are important, yet overlooked, components. I aimed at revising recent estimates of the costs of asthma worldwide. The empirical research involved evaluating the effect of comorbidities on productivity loss among adult asthma patients.
Methods
A literature review was conducted on studies regarding the costs of asthma (January 2008 to January 2015) and subsequently on the effects of comorbidities on productivity. In parallel data from a prospectively evaluated random sample of employed adults with asthma was used and the prevalence of comorbidities measured using a validated self-administered comorbidity questionnaire (SCQ), range 0 β 39, (the higher the score, the higher the level of comorbidity). Productivity loss, including absenteeism and presenteeism, were also measured using validated instruments in 2010 Canadian dollars ().Iusedatwoβpartregressionmodeltoestimatetheadjusteddifferenceofproductivitylossacrosslevelsofcomorbidity,controllingforpotentialconfoundingvariables.ResultsThereviewdemonstratedthatasthmaimposesamajoreconomicburden,howevertherearelargediscrepanciesinthereportedestimates.Thereisalsouncertaintyabouttheindirectcostsofasthmaandtheeffectsofcomorbiditiesonthesecosts.Arandomsampleof284adultswiththemeanageof47.8(SD11.8)wasincluded(68317.5 per week (SD 858.8).Comorbiditywassignificantlyassociatedwithproductivityloss.OneβunitincreaseintheSCQscorewasassociatedwitha141,685 per week more productivity loss than a patient with a SCQ of zero.
Conclusion
This study demonstrates that comorbidities substantially decrease productivity in working asthma patients. Asthma management strategies must be cognizant of the role of comorbidities and should properly incorporate the effect of comorbidity and productivity loss in estimating the benefit of disease management strategies.Medicine, Faculty ofGraduat