Multimorbidity is known to increase clinical management complexity promote osteoporosis treatment hesitancy, but its impact on post-fracture adverse events is unknown. This study aimed to determine the association between multimorbidity and risk of subsequent fracture and post-fracture mortality risk.
45 and Up is a prospective population-based cohort of 267,153 people with questionnaires linked to hospital (Admitted Patients Data Collection –APDC), emergency (Emergency Department Data Collection – EDDC)[1], Pharmaceutical Benefits Scheme (PBS) and Registry of Births, Deaths and Marriages (RBDM)[2] datasets. Fractures and Charlson Comorbidity Index (CCI) were identified from APDC and EDDC, and mortality from RBDM.
Association of comorbidities and post-fracture adverse events was determined using cause-specific Cox model; a competing risk model which produces simultaneous estimates of subsequent fracture and mortality and is recommended for etiological studies. The models were further adjusted for age, weight, prior fracture and falls.
Of the 25,000 persons with fracture, approximately 15% sustained subsequent fractures and 22% died during 8,460 person-years follow-up. Compared to a CCI <2, a CCI ≥ 2 was associated with increased risk of both subsequent fracture [HR 1.38 (95% CI, 1.16-1.64) and 1.59 (95% CI, 1.30 – 1.95) for women and men, respectively] and mortality [HR, 5.16 (95% CI, 4.57 – 5.84) and 4.02 (95%, 3.58 – 4.52) for women and men, respectively]. Of the individual chronic conditions, diabetes and neurological diseases were associated with increased subsequent fracture risk in both genders, while renal disease and dementia contributed to subsequent fracture risk in men only. All chronic conditions were associated with increased mortality risk in both genders (Figure).
The findings that multimorbidity is associated with poor fracture outcomes highlight the need for development of robust framework for fracture management in sicker patients.