Increased risk of osteoporotic fractures in Swedish patients with rheumatoid arthritis despite early treatment with potent disease-modifying anti-rheumatic drugs: a prospective general population-matched cohort study

Abstract

Objective: To study the difference in incidence and risk of fragility fractures between rheumatoid arthritis (RA) patients followed up early in the disease and the general population in Sweden; and the fracture risk changes in RA patients diagnosed in the 1990s and 2000s because of earlier, more potent pharmacological treatment in the later period.

Method: Patients with early RA were recruited from the BARFOT cohort, a Swedish multicentre observational study of early RA patients (n = 2557). All patients fulfilled 1987 American College of Rheumatology criteria and were included between 1992 and 2006. Each patient was matched by gender, age, and residential area with four controls from the general population (n = 10 228). Fractures of forearm, upper arm, and hip were identified by ICD-9 and ICD-10 codes through Swedish national medical registries.

Results: During follow-up of 12.9 ± 4.7 years (mean ± sd), 14% (n = 470) of RA patients and 11% (n = 1418) of controls experienced a fracture (p < 0.001). When dividing the patients and controls into two groups according to inclusion period, an 8 year follow-up time was used. RA patients included in the 1990s had a higher incidence rate (IR) of hip and other fractures. RA patients included in the 2000s had a higher IR of all fracture sites. The hazard ratio of fractures was 1.4 in the total RA cohort, and the risk was increased in both the 1990s and 2000s.

Conclusion: We observed an increased risk of fragility fractures in RA patients diagnosed in both the 1990s and 2000s, despite patients in the 2000s obtaining potent pharmacological treatment early in the disease.

Acknowledgements

This study was supported by grants from the Centre for Clinical Research Dalarna, Falun, Sweden, and the Norrbacka-Eugenia Foundation, Stockholm, Sweden.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supporting Information

Additional Supporting Information may be found in the online version of this article.

Supplementary figure S1: Survival analysis (Kaplan–Meier method): comparison between the total population of RA patients and matched controls over the entire follow-up time.

Supplementary figure S2: Survival analysis (Kaplan–Meier method): comparison between the RA patients included in the 1990s and matched controls over 8 years.

Supplementary figure S3: Survival analysis (Kaplan–Meier method): comparison between the RA patients included in the 2000s and matched controls over 8 years.

Supplementary figure S4: Survival analysis (Kaplan–Meier method): comparison between the RA patients included in the 1990s and 2000s over 8 years.

Supplementary figure S5: Survival analysis (Kaplan–Meier method): comparison between women with RA and matched controls over the entire follow-up time.

Supplementary figure S6: Survival analysis (Kaplan–Meier method): comparison between men with RA and matched controls over the entire follow-up time.

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