Time trends in glucocorticoid use in rheumatoid arthritis: results from a population-based inception cohort, 1980-1994 versus 1995-2007

Abstract

Objective: To examine trends in glucocorticoid (GC) use and dosing among patients diagnosed with rheumatoid arthritis (RA) over time.

Methods: A population-based inception cohort of RA patients diagnosed during 1980-2007 was followed longitudinally through their medical records until death, migration, or December 31, 2008. GC start and stop dates were collected, along with doses in prednisone equivalents.

Results: The study population comprised 349 patients (68% women) diagnosed in 1980-1994 and 464 (69% women) diagnosed in 1995-2007, with a median followup of 15.3 and 5.7 years, respectively. A higher proportion of patients started GCs in their first year of disease in 1995-2007 (68% versus 36%; P < 0.001), but the starting dose (mean 8.7 versus 10.3 mg; P = 0.08) and cumulative dose in the first year of use (mean 1.8g [mean daily dose 4.9 mg] versus 2.1 gm [mean daily dose 5.8 mg]; P = 0.48) were not different. A higher proportion also discontinued GCs in their first year of disease in the 1995-2007 cohort (P < 0.001). These differences in GC initiation and discontinuation persisted throughout followup. Prevalence of GC use was higher in the 1995-2007 cohort for the first 3 years of disease.

Conclusion: More patients are starting GCs early in their disease course now compared to previously, which is consistent with established treatment guidelines. A higher proportion are also discontinuing GCs, but the proportion of patients taking GCs at any given point of disease during the first 4 years is higher now than previously. Despite early addition of a disease-modifying antirheumatic drug, some patients may not be able to discontinue GCs over the long term.

Figure 1

Cumulative incidence of start of glucocorticoids according to time period of rheumatoid arthritis (RA) incidence - 1980–1994 (dashed line) vs. 1995–2007 (solid line), p<0.001.

Figure 2

Cumulative incidence of discontinuation of glucocorticoids for at least 90 days according to time period of rheumatoid arthritis incidence: 1980–1994 (dashed line) vs. 1995–2007 (solid line), (p<0.001).

Figure 3

A. Current prevalence of glucocorticoid (GC) use by rheumatoid arthritis (RA) duration, according to time period of RA incidence: 1980–1994 (dashed line; n=394) vs. 1995–2007 (solid line; n=464). B. Patients who started a disease modifying antirheumatic drug in the first 6 months of RA (red line; 1980–94 n=164, 1995–2007 n=356) vs those who did not (black line; 1980–1994 n=185, 1995–2007 n=108).