ABSTRACT
Purpose: Lifetime risk estimates show that the use of primary total shoulder replacement (TSR) surgery in Australia has increased in recent years, but future demand for surgery has not been estimated. This study aimed to forecast the number of primary TSR procedures likely to be performed in the year 2035, and associated costs to the Australian health system. Method(s): De-identified primary TSR data for 2009-2019 were obtained from the Australian Orthopaedic Association National Joint Replacement Registry. Australian population data (by age and sex) to the year 2021 and population projections to the year 2035 (by age and sex) were obtained from the Australian Bureau of Statistics. Data on average episode of care costs were sourced from the National Hospital Cost Data Collection and private health insurer websites. Procedure rates to the year 2035 were projected according to two scenarios: Scenario 1 assumed that the rate of TSR remained constant from 2019 onwards, with consideration of anticipated population growth and ageing;Scenario 2 assumed a continued increase in the rate of surgery as seen from 2009-2019 plus anticipated population growth and ageing. For Scenario 1, age- and sex-specific rates of TSR in 2019 were calculated and applied to population projections for the years 2020-2035. For Scenario 2, negative binomial regression models (which controlled for age, sex, and year) were used to estimate TSR procedures for the years 2020-2035. For both scenarios, healthcare costs for 2035 were estimated for the projected number of TSR procedures, with average procedure costs for public and private hospitals inflated to 2035 Australian dollars using the Total Health Price Index. Result(s): The use of TSR increased by 242% in Australia from 2009 to 2019 for adults over 40 years of age (from 1,983 to 6,789 procedures). In 2019, 60% of procedures (n=4,062) were performed for females and 73% (n=4,925) were performed for people aged 60-79 years. Fifty-three per cent of procedures in 2019 (n=3,608) were performed for osteoarthritis. Under Scenario 1, the incidence of TSR is predicted to rise from 6,789 procedures in 2019 to 9,676 procedures by 2035 (a 43% increase), at an estimated cost of $AUD 317.69 million. Under Scenario 2, TSR incidence is forecast to increase to 45,295 procedures by 2035 (a 567% increase) at an estimated cost of $AUD 1.49 billion. Under this scenario, 69% of the total forecast costs (equating to $AUD 1.02 billion) relate to the private hospital sector. Conclusion(s): The use of TSR in Australia has increased substantially over a decade, which likely relates to a range of factors including improvements in prosthesis design, improved clinical outcomes for patients, greater surgeon proficiency, and expanded clinical indications for surgery. Under a conservative forecasting scenario, a 43% in the number of procedures is estimated to occur by 2035. However, under an exponential growth scenario that considers growth in TSR rates plus population growth and ageing, Australia would be facing a more than five-fold increase in TSR procedures by 2035. This would have profound implications for the healthcare budget and surgical workforce requirements. Future research is needed to model the impacts of COVID-19 on TSR provision and catch up of unmet need due to elective surgery restrictions and cancellations.Copyright © 2023