Societal and Economic Impact of Informal Caregiving for Musculoskeletal Conditions: A Productivity-Adjusted Life Year (PALY) Study

BACKGROUND: Musculoskeletal conditions (MSCs) are a leading cause of disability and chronic pain globally, yet the long-term economic impact on informal caregivers remains underexplored. The productivity-adjusted life year (PALY) framework offers a novel method for estimating lifetime productivity losses associated with caregiving, providing a broader societal perspective than conventional short-term productivity metrics. OBJECTIVE: To quantify long-term productivity and health-related quality of life among informal caregivers of individuals with MSCs in Australia, using PALYs and quality-adjusted life years (QALYs) over 30 years. METHODS: A dynamic life-table model was developed to simulate two cohorts-informal caregivers of people with MSCs and a matched non-caregiver control group-across a 30-year time horizon (2024-2053). The model incorporated Australian age- and sex-specific data on caregiver prevalence, mortality, labour force participation, absenteeism, and presenteeism. PALYs were calculated by combining full-time equivalent (FTE) labour force participation with productivity indices. QALYs were estimated using health utility values adjusted for caregiver-specific disutility. Productivity losses were monetized using GDP per FTE worker. Deterministic and probabilistic sensitivity analyses were conducted to assess model robustness. RESULTS: Informal caregiving for MSCs resulted in an estimated loss of 896,523 PALYs and 487,950 QALYs, with an associated productivity cost of AUD $203.3 billion over 30 years ($44,808 per carer). On an annual basis, this equates to 29,884 PALYs and AUD $6.78 billion in lost productivity. Female carers bore a disproportionate share of the burden, accounting for 53% of PALYs lost and 59% of QALYs lost. The probabilistic sensitivity analysis indicated the base-case was likely conservative, estimating mean productivity losses of AUD $252.1 billion, with a 95% CI ranging from AUD $249.5 billion to $254.6 billion, reflecting parameter uncertainty within model assumptions. CONCLUSIONS: This study provides the first application of the PALY framework to informal caregivers of MSCs in Australia and globally. Informal caregiving for MSCs imposes a substantial and under recognized economic burden. Applying the PALY framework provides compelling evidence for incorporating caregiver productivity into economic evaluations and policy decisions aimed at supporting the informal care workforce. Findings highlight the need for targeted workplace and policy measures, particularly to address the disproportionate impact on women.