Introduction___________________________

Rheumatoid arthritis (RA) is the most common chronic inflammatory arthritis with no known cause that leads to joint destruction and disability [1, 2]. RA is distributed in all ethnic groups all over the world [3].

The total prevalence of disease has been estimated to be 0.57% for females and 0.14% for males [4]. RA imposes considerable social and economic burdens because of its chronic nature, subsequent handicap, and long-term disability [5]. In the USA, the average capitation of medical costs for bone and joint patients in 1996 was $3578; the total spent was $193 billion, which was equivalent to 2.5% of the gross domestic product.

Treatments for RA include medications, biological treatments, and surgery [6]. In spite of a good understanding of the pathogenesis of this disease, the availability of criteria and newer diagnostic tests, earlier and more accurate diagnosis, and the considerable number of novel treatments, RA still causes many disabilities; some patients are even in danger of an early death [7-9].

Cognitive Behavioral Therapy (CBT) is known as an efficient short-term goal-oriented modality of psychotherapy [10]. Albeit primarily applied for mood disorders, the role of CBT has expanded to include states of chronic pain [10].

In combination with medical treatments, CBT has been proposed as an integral therapeutic modality in RA [11]. CBT has led to positive outcomes by enhancing coping capacities and reducing catastrophic thinking about pain [12, 13]. Many studies have been done on RA and other rheumatologic diseases which have investigated the effects of teaching patients about treatment processes and side effects of diseases [14, 15]. However, there are some questions about the effectiveness of CBT on significant results and the underlying mechanism involved in the ameliorative function of CBT. A pilot study by Ferguson et al. proposed a positive impact of CBT on RA patients’ adherence to treatment [16]. Considering the remaining ambiguities in past studies, the heavy burden of RA in Iran and the cost and side effects of treatment, the current study was designed to more precisely explore the effect of this type of psychotherapy on the lifestyle of Iranian rheumatoid arthritis patients. Researchers painstakingly tried to find the alteration pattern of various domains of AIMS-2 after CBT training.

Patients and Methods__________________________

This case control study was conducted at the rheumatology clinic of Shariati Hospital, Tehran, Iran. Diagnoses of RA were confirmed by a rheumatologist based on American College of Rheumatology (ACR) criteria. Enrolled patients were residents of Tehran and were in the age range of 16-65. The patients were instructed to contact the research team by phone on a regular basis. Exclusion criteria were the presence of comorbidities which could potentially affect the patient`s quality of life, residence in homes for the elderly or any other nursing centers, and having a cognitive behavioral disorder. Moreover, patients with a disability that prevented the rheumatologist from educating them or patients with American Rheumatism Association criteria for functional class (ARA) >2 were not eligible for this study.

Data collection instrument

The Arthritis Impact Measure Scale (AIMS-2) questionnaire was applied to assess the patients’ quality of life. AIMS-2 evaluates the twelve factors of mobility, hand and finger function, walking, arm function, pain, self-care, daily household tasks, social activities, social support, work, depression, and stress. It also collects personal information, the address and telephone number of the patient or his/her companions who give the information. After questions asking for demographic and contact information, questions assessing life quality in RA patients ensue.

The questionnaire consisted of 78 sections. The first 57 questions covered the 12 above-mentioned quality-of-life factors. The 58^th item that was applied specifically for this study evaluated the satisfaction scale of each of these twelve cases. The score of each case was registered between 0-10 (0 indicating a good situation of health and 10 indicating a weak situation). Hence, lower scores on the AIMS-2 indicate a higher quality level.

Validation of Persian version of AIMS-2

This questionnaire was translated once into Persian, and then it was back-translated to English by a translator with no knowledge of this research project. The back-translated version was compared with the original questionnaire. The test and re-test were compared by sending the questionnaires after 4 weeks to be completed again by the patients. No data was missing. Meanwhile, three rheumatologists evaluated the questionnaire for content validity.

To examine the face validity prior to launching the study, the questionnaire was completed by 20 patients. A Cronbach`s α coefficient of 0.84 revealed acceptable internal consistency of the adapted AIMS-2.

Patient enrollment and data collection

The enrolled cases were entered into the study through convenience sampling by blocked random allocation. Ninety participants were divided into three subgroups: CBT (CBT+), non-CBT (CBT-) and Control. Double blinding was also considered in the management of patients and allocator.

After signing an informed consent form, eligible patients completed the questionnaire in the presence of the main researcher who could answer the presumable problems.

The Control group received conventional RA treatment, while the CBT intervention group (CBT+ subgroup) attended training (7 two-hour sessions, twice a week). The non-CBT group (CBT- subgroup) got a training plan about diet and instructions for avoiding drug-induced osteoporosis. On the first day of the study and in the last session of training, all participants completed the AIMS-2 forms.

Calculation of sample size

The sample size was calculated based on a reference randomized clinical trial by Sharpe et al. (Power=80% and a=0.005) [17]. The calculated sample size was 30 patients for each subgroup (CBT+, CBT-, and Control). Overall, 90 RA cases were enrolled in the current study.

Data analysis

Mean and standard deviation were used to indicate descriptive statistical variables, and absolute frequency and prevalence were used to indicate qualitative statistics. For descriptive analysis based on objectives, one-way ANOVA, Mann-Whitney U, independent-samples T test, Chi square, and Kruskal-Wallis tests were used. Collected data was analyzed using SPSS 22.0 (Chicago, IL). A p-value=0.05 was considered significant.

Ethical issues

The study proposal was approved by the Ethics Committee of Tehran University of Medical Sciences. All participants were required to sign an informed consent form. The research team was committed to absolute confidentiality of patient information. After the completion of data gathering, codes were used instead of assigned names.

Results_______________________________

The studied population comprised 72 (80%) female and 18 (20%) male cases. There was no significant difference in age, gender, or education level among the three groups. The demographic items of the studied population are summarized in Table 1.

Comparing pre-CBT AIMS-2 scores

All parameters were compared between the three subgroups at the beginning of the study and prior to undertaking interventions. No significant difference was noted in the various AIMS-2 features, except in self-care. CBT- patients had the highest self-care score, while CBT+ patients had the lowest self-care score (p=0.001). The pre-CBT AIMS-2 scores are tabulated in Table 2.