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Anti-TNF therapy in rheumatoid arthritis. Effects on and predictors of work disability

Olofsson, Tor O LU (2016) In Lund University Faculty of Medicine Doctoral Dissertation Series 2016:16.
Abstract
Objectives: To study: (I) work-loss seen as sick leave and disability pension before and after the start of first anti-TNF therapy in Swedish regional and national RA cohorts; (II) baseline predictors of a good future work prognosis at diagnosis and after anti-TNF start with a special focus on the impact of the disease activity level and the disease duration at treatment start.



Methods: RA patients were identified in the regional biologics register in Southern Sweden, SSATG, the national register over RA patients, SRQ, and the national biologics register, ARTIS, and linkage was performed to the Social Insurance Agency Register for day-level data on sick leave and disability pension. The development of these work-loss... (More)
Objectives: To study: (I) work-loss seen as sick leave and disability pension before and after the start of first anti-TNF therapy in Swedish regional and national RA cohorts; (II) baseline predictors of a good future work prognosis at diagnosis and after anti-TNF start with a special focus on the impact of the disease activity level and the disease duration at treatment start.



Methods: RA patients were identified in the regional biologics register in Southern Sweden, SSATG, the national register over RA patients, SRQ, and the national biologics register, ARTIS, and linkage was performed to the Social Insurance Agency Register for day-level data on sick leave and disability pension. The development of these work-loss measures over selected time-periods after diagnosis and after anti-TNF start were then computed for patients and, in relevant cases, for matched reference subjects from the general population. Predictors were assessed by linear and logistic regression analysis as well as with survival analysis including Cox regression.



Results: From start of the first anti-TNF therapy until 6 months after, a reduction in sick leave of almost 30% was seen in working-age RA patients. This was not due to secular trends and only to some extent offset by an increase in disability pension. Regarding cumulative 3-year work-loss after RA diagnosis, the most important predictor of a favorable prognosis was the baseline work ability level, but low HAQ-values, low values of the more subjective DAS28 components (VAS pain, VAS global and tender joint count) and high education level were also predictors of less future work-loss. We also reported that after first anti-TNF start no difference in the decline of work-loss over 5 years between patients with high vs. moderate disease activity (~40% in both groups) was seen. Furthermore, for patients lacking work ability at anti-TNF start, we could show that the chance of regaining all or some of it during 3 years of follow-up was 35% if they started treatment within 5 years of symptom onset, and less than half of that for later treatment starts. This effect seemed to be channeled through the impact of disease duration on disability pension status.



Conclusion: Anti-TNF therapy seems to lower monthly work-loss levels during the first treatment year and a continuous decline is also seen over 5 years with no difference between patients starting treatment with high vs. moderate disease activity. Out of patients lacking work ability at anti-TNF start, those with less than 5 years disease duration are more likely to get it back. Thus, anti-TNF therapy seems to add positive outcomes for work ability to its favorable clinical effects in RA patients. (Less)
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author
supervisor
opponent
  • Professor Symmons, Deborah, The University of Manchester
organization
publishing date
type
Thesis
publication status
published
subject
in
Lund University Faculty of Medicine Doctoral Dissertation Series
volume
2016:16
pages
108 pages
publisher
Department of Clinical Sciences, Lund University
defense location
Reumatologens föresläsningssal, Skånes universitetssjukhus i Lund
defense date
2016-02-12 09:00
ISSN
1652-8220
ISBN
978-91-7619-242-9
language
English
LU publication?
yes
id
237972cc-2463-42d1-ad21-05ec1dbb5861 (old id 8566300)
date added to LUP
2016-01-27 08:04:07
date last changed
2016-09-19 08:44:51
@phdthesis{237972cc-2463-42d1-ad21-05ec1dbb5861,
  abstract     = {Objectives: To study: (I) work-loss seen as sick leave and disability pension before and after the start of first anti-TNF therapy in Swedish regional and national RA cohorts; (II) baseline predictors of a good future work prognosis at diagnosis and after anti-TNF start with a special focus on the impact of the disease activity level and the disease duration at treatment start.<br/><br>
 <br/><br>
Methods: RA patients were identified in the regional biologics register in Southern Sweden, SSATG, the national register over RA patients, SRQ, and the national biologics register, ARTIS, and linkage was performed to the Social Insurance Agency Register for day-level data on sick leave and disability pension. The development of these work-loss measures over selected time-periods after diagnosis and after anti-TNF start were then computed for patients and, in relevant cases, for matched reference subjects from the general population. Predictors were assessed by linear and logistic regression analysis as well as with survival analysis including Cox regression.<br/><br>
<br/><br>
Results: From start of the first anti-TNF therapy until 6 months after, a reduction in sick leave of almost 30% was seen in working-age RA patients. This was not due to secular trends and only to some extent offset by an increase in disability pension. Regarding cumulative 3-year work-loss after RA diagnosis, the most important predictor of a favorable prognosis was the baseline work ability level, but low HAQ-values, low values of the more subjective DAS28 components (VAS pain, VAS global and tender joint count) and high education level were also predictors of less future work-loss. We also reported that after first anti-TNF start no difference in the decline of work-loss over 5 years between patients with high vs. moderate disease activity (~40% in both groups) was seen. Furthermore, for patients lacking work ability at anti-TNF start, we could show that the chance of regaining all or some of it during 3 years of follow-up was 35% if they started treatment within 5 years of symptom onset, and less than half of that for later treatment starts. This effect seemed to be channeled through the impact of disease duration on disability pension status. <br/><br>
<br/><br>
Conclusion: Anti-TNF therapy seems to lower monthly work-loss levels during the first treatment year and a continuous decline is also seen over 5 years with no difference between patients starting treatment with high vs. moderate disease activity. Out of patients lacking work ability at anti-TNF start, those with less than 5 years disease duration are more likely to get it back. Thus, anti-TNF therapy seems to add positive outcomes for work ability to its favorable clinical effects in RA patients.},
  author       = {Olofsson, Tor O},
  isbn         = {978-91-7619-242-9},
  issn         = {1652-8220},
  language     = {eng},
  pages        = {108},
  publisher    = {Department of Clinical Sciences, Lund University},
  school       = {Lund University},
  series       = {Lund University Faculty of Medicine Doctoral Dissertation Series},
  title        = {Anti-TNF therapy in rheumatoid arthritis. Effects on and predictors of work disability},
  volume       = {2016:16},
  year         = {2016},
}