Background/Purpose:

Although the effects of tobacco use on disease onset, severity, and response to therapy have been well studied in rheumatoid arthritis (RA), there is little data addressing the effect of smoking on the functional status of patients with RA.  This study assesses the relationship between tobacco use and change in functional status over time in patients with RA.

Methods:

Retrospective analysis of 121 subjects with confirmed RA in an ethnically diverse outpatient rheumatology clinic at a public hospital.  Primary outcome was the difference between baseline HAQ score and repeated assessment of HAQ 2-5 years later. Primary predictor variable was current smoking at baseline.  Covariates included time between HAQ assessments, age, gender, rheumatoid factor positivity, baseline HAQ and DAS28-ESR scores, synthetic DMARD use, biologic use, and disease duration.  Student’s t-test was used to compare the mean change in HAQ over time between smokers and non-smokers.  Association between smoking and change in HAQ over time, controlling for all covariates, was assessed with multivariate linear regression.  Multivariate logistic regression was then used to assess the odds of achieving the accepted clinically meaningful improvement in HAQ score of -0.22¹ during this time period.

Results:

Of the 121 subjects, 14 (12%) were current smokers at baseline assessment, 108 (89%) were female, and 114 (94%) were non-Caucasian.  Mean age was 53 (+13).  Mean baseline HAQ score was 1.32, mean time between HAQ assessments was 3.5 years, and mean change in HAQ over time was 0.088.  Individual change in HAQ score ranged from -1.88 to 2.0.  Mean change in HAQ was 0.411 among smokers and 0.046 among non-smokers (p = 0.043).  One of 14 smokers (7%), and 33 of 107 non-smokers (31%), achieved a clinically meaningful improvement in HAQ during this time period.  Multivariate linear regression demonstrated that smoking is independently associated with a worsening HAQ over time (coefficient= 0.33, p= 0.047).  Multivariate logistic regression demonstrated that smoking decreased the odds of achieving a clinically meaningful improvement in HAQ (OR 0.07, 95% CI 0.01-0.83).

Conclusion:

Cigarette smoking was associated with worsening functional status among patients in this cohort over a mean time of 3.5 years. In addition, the odds of achieving a clinically meaningful improvement in functional status during this follow-up period were significantly lower in smokers as compared to non-smokers. 

¹Wolfe. J Rheumatol 2005; 32:583.

---

« Back to 2012 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/smoking-is-associated-with-worsening-functional-status-over-time-in-a-diverse-cohort-of-patients-with-rheumatoid-arthritis/