OBJECTIVES

Literature and analysis of Spanish National-Health-Survey (NHS) show patients with osteoarthritis (OA) to be more frequently associated with comorbidities and pain than non-OA persons. Consequently, OA incur in additional healthcare resource utilization (HRU) and related costs. This work estimates the excess in non-therapeutic HRU and incremental cost driven by extra comorbidities and pain in OA from the Spanish National Health System perspective.

METHODS

The 2017-publicly-available NHS, a cross-sectional, nationwide representative, including 23,089 adults (5,234 with self-reported physician OA diagnosis; 70.8% women, 69.9 years) database was analysed. Thirty-two comorbidities, obesity, metabolic syndrome, and two composite-comorbidity measurements (the abridged-Charlson-Comorbidity Index and the Functional-Comorbidity Index [FCI]) were quantified as the person´s comorbidity burden together with pain severity. Unit price multiplied by annual HRU was computed as related costs. Average adjusted per-patient-per-year (PPPY) was used to express HRU and cost burden. The excess HRU and cost attributable to comorbidities and pain in OA compared to non-OA was estimated fitting multivariate models adjusting by confounders and applied sequentially including each time a higher burden of comorbidity and pain.

RESULTS

Compared with non-OA persons, excess cost in OA was mainly attributable to comorbidities included in FCI and severity of pain; from an excess of €463 (95%CI: 332;594) PPPY in the covariates-only model to -€220 (-360;-80) in the covariates+FCI+pain model (p<0.001). Incremental days in-hospital stay and medical visits utilization accounted by 45% and 35% of excess cost, respectively; from €157 (40;273) to -€147 (-272;-21) in hospitalization and from €194 (161;227) to -€48 (-83;-14) in medical visits (both p<0.001).

CONCLUSIONS

In a representative nationwide sample in Spain, the excess burden of comorbidity and pain seems to be the determinants of additional resource utilization and incremental non-therapeutic cost in OA compared to non-OA persons. Meaningful drivers were the extra consumption of medical visits and days of in-hospital stay.