Rheumatoid arthritis (RA) is a progressive disease, often leading to disability. Because the disease course develops rapidly during the first years after diagnosis, more knowledge is needed about the early disease course to minimize later disability. This thesis describes the course of disability in early RA such as hand function, pain intensity, activity limitation and sick leave. In addition, this thesis compares disability between women and men and compares disability between RA patients and referents.

This thesis is primarily based on data from the 320 patients that were included in the multi-centre project in Sweden called ‘Early interventions in rheumatoid arthritis’ (TIRA). A wide range of outcome variables was registered between 1996 and 2006 during regular follow-ups from time for diagnosis through the eight-year follow-up. Outcome regarding disease activity and disability of RA patients still remaining in TIRA at the three and five year follow-up respectively are used in this thesis. Data concerning sick leave were obtained for the patients during six years (1993-2001) – three years before and three years after diagnosis. Referents were included in two of the studies. Data regarding disability in referents were obtained according to hand function and activity limitation using the Health Assessment Questionnaire (HAQ). Data for sick leave were obtained for six years in referents, for the same period as the RA patients.

For most variables, disability in RA was most pronounced at time of diagnosis but before intervention started. Disability was then reduced already at the 3-month follow-up and thereafter affected but stable during the following five years. The exception was participation, reflected by sick leave, a variable that was stable from inclusion to three years from diagnosis. Activity limitation, pain intensity and sick leave in RA that represents different aspects of disability were explained by other aspects of disability and contextual factors rather than by disease activity. RA affects women and men differently in some aspects. Women had more severe course of activity limitations than men according to HAQ. Men were more affected than women in range of motion, although the differences were small in a clinical perspective. However, pain intensity and frequency of sick leave did not differ between women and men. Patients with RA have pronounced disability in relation to referents although several variables improve soon after diagnosis. This discrepancy refers to hand function as well as activity limitations and sick leave. The frequency of sick leave increased during the year before diagnosis in relation to referents and was thereafter high compared to sick leave in referents.

Rheumatoid arthritis (RA) is a chronic inflammatory disease, which often leads to disability. This study is based on three years’ follow-up data generated by patients included during 27 months 1996-1998 in a Swedish multi-centre project named ‘early interventions in rheumatoid arthritis’ (TIRA). Disease activity, disability and health-related quality of life (HRQL) were assessed by clinical and laboratory analyses, and self-reported estimations. The course during three years and relations between clinical/laboratory assessments versus HRQL were studied separately in women and men. The relation between grip force and self-reported activity limitations was analysed, and finally the use and effects of assistive devices were evaluated separately for women and men.

Clinical/laboratory assessments and self-reported HRQL were substantially affected at the time for diagnosis, but the relations between clinical/laboratory assessments and self-reported HRQL were weak. Among the studied clinical/laboratory variables used here grip force, walking speed, and possibly physician’s global assessment of disease activity showed most stable relationships with the HRQL. However, the time course of clinical/laboratory and selfreported HRQL measurements followed similar patterns. Thus, most variables had improved considerably at the 3- and 6-months’ follow-ups and then remained stable but still affected over three years. An exception was the SF-36 scale ‘general health’, which was reduced to the same extent during the whole study period.

As judged by the ‘Health Assessment Questionnaire’ (HAQ) and ‘Evaluation of Daily Activities Questionnaire’ (EDAQ), activity limitations were more pronounced in women than in men. By contrast, as reflected by ‘Signals of Functional Impairment’ (SOFI), men had slightly more affected function of the hands and upper extremities. Women with RA had about half of the grip force compared to male patients, which is in accordance with the differences between healthy women and men. At diagnosis, the grip force was reduced to about 30% in RA patients compared to healthy referents of the same sex. Already three months later, it improved but was still reduced to about 50% of healthy referents.

Further analyses revealed that HAQ and EDAQ were strongly related to grip force independently of sex. Grip force below 114 N was found to be associated with substantial activity limitation in women as well as in men. Assistive devices (ADs) were more frequently used by women (78%) than men (54%), and were found to reduce activity limitations. The subgroups of women and men using ADs were comparable regarding disease activity and disability, and were generally more affected regarding activity limitations, compared to the subgroups that did not use ADs. Within the subgroups of patients using ADs, women and men had equivalent HAQ status and ADs were reported to reduce activity limitations in both women and men with recent-onset RA.

The weak relation between clinical/laboratory assessments and self-reported HRQL supports the results by others. By means of HAQ, more pronounced activity limitations have been reported previously in women with RA, compared to male patients. In the present study, similar differences were recorded by EDAQ. Further analyses showed that reduced grip force was closely related to activity limitations independently of sex. This offers a new explanation to poor female outcome recorded by HAQ.