Aims: To compare hospitalisations, morbidity and mortality in Rheumatoid Arthritis patients(RA) by age.
Methods: RA patients were identified using linked administrative health (ICD codes 714.0–714.9 and M05.00–M06.99) and adverse drug reactions from E-codes in the Morbidity datasets in WA from 1995–2014. Patients grouped by geriatric age cohorts (“young old”(60 – 69 years), “old”(70 – 84 years) and “old old”(85+ years), were compared to matched controls.
Results: Of a total of 17,125 RA patients (68% female); 58% were over 60, 22% were over 70, and 20% over 80 years.) Patients over 60 years accounted for 59.2% of 50,353 total admissions: 30% in in the 70 – 84 age group . Admissions for adverse drug reaction was highest in patients aged 60 plus (71 – 79%); highest risk group 70 – 84 years (41 - 48%). Mortality (MR) rate per 1000 person years (overall 25.15; SD 24.63-25.67) increased exponentially with age: 60 – 69, 44.32 (SD 42.71 – 45.97); 70 – 84, 68.83 (66.37 – 71.37); 85+, 131.65 (115.68 – 149.20). Standardised MR was overall 2.58 (2.51 – 2.65) and although higher in 60 – 69 years (4.08 (3.92 – 4.23), was not increased in 70 – 84 years (1.82; 1.76 – 1.89) and in 85+ (0.94;0.83 – 1.07) (survivors). HR of death by age groups (univariate) increased exponentially from 36.8 (60 – 69 years ) to 129 (85+) and multivariate from 16.7 (SD 12.4 – 22.3); to 57.8 (SD 42 – 79.5).
Conclusion: RA patients over 60 are at the highest risk of admission (all cause), admission for ADR and highest risk of mortality.