Trajectory of excess healthcare consultations, medication use, and work disability in newly diagnosed knee osteoarthritis: a matched longitudinal register-based study

Abstract

Purpose: To estimate the excess healthcare use and work disability attributable to knee osteoarthritis (OA) in the first 5 years following diagnosis.

Methods: Among individual aged 40-80 years who resided in Skåne on 31^st December 2008, we identified those with a main diagnosis of knee OA during 2009-2014 and no previous diagnosis of any OA from 1998 (n = 16,888). We created a comparison cohort matched (1:1) by sex, age, and municipality from individuals with no OA diagnosis (at any site) during 1998-2016. We compared healthcare use and net disability days for 60 months following diagnosis between the two groups. We applied a survival-adjusted regression technique controlling for sociodemographic characteristics as well as pre-diagnosis outcome and comorbidity.

Results: The estimated 5-year incremental effects of knee OA per-patient were 16.8 (95% CI: 15.8, 17.7) healthcare consultations, 0.7 (0.4, 1.1) inpatient days, 420 (372, 490) defined daily dose of prescribed medications, and 21.8 (15.2, 30.0) net disability days. Primary care consultations constituted about 73% of the excess healthcare consultations. Most of these incremental effects occurred in the first year after diagnosis. Better survival in the knee OA group accounted for 0.7 (95% CI: 0.5, 0.8) and 1.4 (0.7, 2.6) of the excess healthcare consultations and net disability days, respectively. Both estimated total and incremental resources use were generally greater for women than men with knee OA.

Conclusion: Knee OA was associated with considerable excess healthcare use and work disability independent of pre-diagnosis resources use, comorbidity, and sociodemographic characteristics.

Keywords: Healthcare consultation; Incremental analysis; Knee osteoarthritis; Sweden; Work disability.