Introduction:
Lost to follow-up (LTFU) rheumatoid arthritis (RA) patients constitute a population that potentially experiences worsening of their disease. This study aimed to determine the frequency of LTFU and the possible associated factors in newly diagnosed RA patients in our outpatient clinic.

Material and methods:
A retrospective cohort study was conducted using 260 newly diagnosed RA patients. Those who did not attend their scheduled appointment for more than 3 months were defined as LTFU. We used a Likert scale questionnaire to explore the perception and the possible reasons for LTFU by phone. Bivariate and multivariate logistic regression analyses were performed to explore the factors associated with LTFU.

Results:
There were 65 patients (25%) who were LTFU. We contacted 34 of them and selected 34 age-matched routinely followed-up (RFU) patients as controls. The reasons for LTFU were distance from house to hospital constraints (76%), busy (56%), transportation constraints (38%), dissatisfaction with the outpatient clinic service (21%), lack of information about their disease (18%), having other comorbidities that compelled them to go to another department’s clinic (15%), difficulties understanding the clinic registration flow system (9%), and having minimal symptoms (6%). Using the c² test, we found that transportation constraints and busyness were significantly different between LTFU and routinely followed up patients (p-value 0.008 and 0.200, respectively). After multivariate analysis, transportation constraints remained a significant factor (OR = 6.397; 05% CI: 1.622–25.228).

Conclusions:
Among newly diagnosed RA patients, 65 (25%) were LTFU. Transportation constraints and busyness were factors associated with LTFU. Further multivariate analysis showed that the factor transportation constraints was significantly associated with LTFU of RA patients in this study.