Journal Article

Predicting the duration of sickness absence due to knee osteoarthritis: a prognostic model developed in a population-based cohort in Sweden

Farrants, Kristin, Gémes, Katalin, Friberg, Emilie, Bottai, Matteo, Alexanderson, Kristina, Almondo, Gino, Frumento, Paolo, Holm, Johanna

2021

Overview

Background Predicting the duration of sickness absence (SA) among sickness absent patients is a task many sickness certifying physicians as well as social insurance officers struggle with. Our aim was to develop a prediction model for prognosticating the duration of SA due to knee osteoarthritis. Methods A population-based prospective study of SA spells was conducted using comprehensive microdata linked from five Swedish nationwide registers. All 12,098 new SA spells > 14 days due to knee osteoarthritis in 1/1 2010 through 30/6 2012 were included for individuals 18–64 years. The data was split into a development dataset (70 %, n spells =8468) and a validation data set (n spells =3690) for internal validation. Piecewise-constant hazards regression was performed to prognosticate the duration of SA (overall duration and duration > 90, >180, or > 365 days). Possible predictors were selected based on the log-likelihood loss when excluding them from the model. Results Of all SA spells, 53 % were > 90 days and 3 % >365 days. Factors included in the final model were age, sex, geographical region, extent of sickness absence, previous sickness absence, history of specialized outpatient healthcare and/or inpatient healthcare, employment status, and educational level. The model was well calibrated. Overall, discrimination was poor (c = 0.53, 95 % confidence interval (CI) 0.52–0.54). For predicting SA > 90 days, discrimination as measured by AUC was 0.63 (95 % CI 0.61–0.65), for > 180 days, 0.69 (95 % CI 0.65–0.71), and for SA > 365 days, AUC was 0.75 (95 % CI 0.72–0.78). Conclusion It was possible to predict patients at risk of long-term SA (> 180 days) with acceptable precision. However, the prediction of duration of SA spells due to knee osteoarthritis has room for improvement.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Age / Arthritis / Care and treatment / Codes / Country of birth / Diagnosis / Disability pensions / Duration / Employment / Epidemiology / Family physicians / Forecasts and trends / Health aspects / Health care policy / Injuries / Insurance agencies / Internal Medicine / Knee / Knee osteoarthritis / Medical prognosis / Medicine / Medicine & Public Health / Morbidity / Musculoskeletal diseases / Orthopedics / Osteoarthritis / Population / Population studies / Prediction / Prediction models / Prescription drugs / Prognosis / Rehabilitation / Rheumatology / Sick leave / Sickness absence / Sports Medicine / Unemployment / Variables / Worker absenteeism