The relation between clinical characteristics and mental health in patients with rheumatoid arthritis

Design

This research was part of a cohort designed to assess the predominant patterns of clinical management of Brazilian patients with RA in everyday practice. A cross-sectional study was carried out, using a quantitative description of trends in a sample of the population²⁴.

Participants

We analyzed data from a larger study coordinated by the RA outpatient clinic of a public institution, between August 2015 and April 2016. The inclusion criteria for the study were: (1) meeting the 2010 American Rheumatism Association (ARA) or American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) classification criteria for RA (Aletaha et al., 2010; Arnett et al., 1988); (2) age 18 years or older; and (3) documented medical record data from at least six months of follow-up at their health center before enrolling in the study. A total of 1115 participants were assessed, of whom 18 were excluded for not having RF data, 315 for not having Anti-CCP values, 318 for not having Mental SF-12 data, one for not having sleep data, one for not having depression data, and one for not having a CDAI, totaling 461 participants. Table 1 presents the sociodemographic data of the participants.

Data collection procedures

The research was conducted in 11 Brazilian centers specializing in the treatment of patients diagnosed with RA. Most of the information was collected during medical consultations, while previous medical records served as secondary sources for biomarkers such as RF and Anti-CCP, which were tested prior to the patients’ arrival at the outpatient clinic. All data was stored in electronic medical records and compiled into a central database. There were three evaluation points.

During the initial medical visit, sociodemographic information and lifestyle habits were collected. At this stage, the duration of the disease, RF positivity, and Anti-CCP levels were assessed. Additionally, participants were interviewed about how they managed stress, anxiety, depression, sleep quality, and pain perception. Pain perception was assessed using the Visual Analog Scale (VAS), with scores ranging from zero (no pain) to 100 (maximum pain). The following scales were also applied: the Health Assessment Questionnaire (HAQ), the Disability Index (DI), the 12-item Health Survey (SF-12), and the Clinical Disease Activity Index (CDAI). During the subsequent follow-up and final appointments, the previous collected data were reviewed to monitor the progression of the disease.

Instruments

The following instruments were administered during the evaluations:

1. 1)

   Sociodemographic and health conditions questionnaire.

The questionnaire was developed by the researchers and aimed to collect data on socioeconomic profile, family history of RA, presence of other autoimmune diseases or associated conditions, personal history of comorbidities, and lifestyle habits (such as smoking, alcohol consumption, and physical activity) of the participants. It also included measures of anxiety, stress, non-restorative sleep, and depression, assessed using a questionnaire adapted from Sokka et al. (2009), based on the Multi-Dimensional Health Assessment Questionnaire (Pincus et al., n.d.). The response options were: “unable to do” (−1), “no difficulty’ (0), “some difficulty” (1), and “much difficulty” (2). In the present study, the Cronbach’s alpha coefficient was 0.811 (p < 0.001) for the total scale.

1. 2)

   The Health Assessment Questionnaire (HAQ) Disability Index (DI) – HAQDI^25,26.

The HAQ-DI is used to monitor the progression of the disease and the effectiveness of the treatment, providing insight into the functionality of the patients. It is a self-assessment questionnaire made up of 20 questions related to daily activities, covering eight components that assess the musculoskeletal system. These components cover tasks such as dressing, getting up, eating, walking, personal care, reaching, grip strength, and other related activities. Each question has four answer options, ranging from zero to 3: “no difficulty at all” (0), “with some difficulty” (1), “with great difficulty” (2) and “unable to perform” (3)”. Higher scores indicate greater disability. Cronbach’s alpha was 0.811 (p < 0,001).

1. 3)

   12-Item Health Survey (SF-12)^27,28.

The SF-12 is a questionnaire used to assess health-related QoL from the patient’s perspective, asking respondents to consider their health status over the past four weeks. It emerged as a simplified version of the SF-36, with the same eight domains of health outcomes, including physical functioning (PF), role limitations due to physical problems (RP), bodily pain (BP), general health perceptions (GH), energy and vitality (VT), social functioning (SF), role limitations due to emotional problems (RE) and mental health (MH). The SF-12 consists of a combination of 12 closed and multiple-choice questions to calculate the three final scores for the physical, mental, and health-related QoL dimensions. The questionnaire ranges from zero to 100, with higher scores indicating better QoL. Scores approaching 50 reflect a situation similar to the general population, while values below 50 indicate a lower QoL than the population average. Cronbach’s alpha was 0.960 (p < 0,001).

1. 4)

   Clinical Disease Activity Index (CDAI)^29,30.

The CDAI is a measure of RA activity, which considers a series of parameters calculated by adding up the number of painful and swollen joints (28 joints), as well as the global assessment of disease activity by the patients and the doctors, both classified on a scale of zero to 10. The total CDAI score ranges from zero to 76 and is used to classify RA activity into four levels: remission (≤ 2.8), low (2.9–10), moderate (10.1–22), and high (> 22). Dissanayake et al. (2022) found a Cronbach’s alpha coefficient of 0.868 in their validation of the instrument.

Ethical procedures

All methods were performed in accordance with the relevant guidelines and regulations.

Informed consent was obtained prior to participation, all individuals received detailed information about the study and signed a Free and Informed Consent Form confirming their voluntary agreement to participate and to allow publication of the anonymized data. All participants were informed that their identities would remain confidential and that responses would be fully anonymized.

The research team made sure that the entire data collection process respected participants’ privacy and followed ethical procedures, including the protection of sensitive information. Participants were also informed that the instruments used posed minimal risk to their physical or psychological health.

Data analysis

Network analysis was conducted to explore the associations among the variables. It was performed using the EBICglasso method, aiming to remove spurious and weak correlations, examine the strength of the identified associations in the regression model, and explore their connections with clinical and mental health measures. This method allowed for a visual and statistical examination of the relationships between biological (e.g., rheumatoid factor, Anti-CCP), clinical (e.g., Clinical Disease Activity Index – CDAI, joint pain, fatigue, HAQ), and psychosocial variables (e.g., SF-12 Mental and Physical Health components: stress, anxiety, depression, and sleep disturbances).

In network analysis, each variable is represented as a node, and the associations between variables are depicted as edges. The thickness and color of the edges reflect the strength and direction of the associations, respectively. Directionality was determined using partial correlations: blue edges indicate positive associations, red edges indicate negative associations, and the absence of an edge suggests that, after controlling for all other variables, there is no statistically significant relationship between the corresponding nodes³¹.

The relations identified in network analysis were included in a multiple linear regression model, including as predictor the CDAI, fatigue, joint pain, HAQ, Physical SF-12, Multi-Dimensional Health Assessment Questionnaire (report of depression, sleep, anxiety, and stress symptoms), and as an outcome variable mental health (Mental SF-12). Therefore, the analyses sought to answer which variables have the greatest association with mental health of the patients.