Early diagnosis is an optimal target for better outcomes in rheumatoid arthritis (RA) in clinical practice [1,2], because early treatment is associated with improved outcomes [2-4]. Furthermore, a UK National Audit Office report concluded that initial management in secondary care of adopting an early diagnosis approach was more cost-effective compared to general physician referral [5]. Despite this, delays occur between the patient seeking medical attention and assessment by a rheumatologist for treatment initiation. These delays occurred at several stages, including the time from symptom onset to assessment in primary care, primary care assessment to secondary care rheumatology referral, rheumatology referral to rheumatology assessment and rheumatology assessment to initiation of disease-modifying antirheumatic drugs (DMARDs) [6].

When considering interventions to address this problem, it is informative to account for the components of the patient journey that contribute to delayed diagnosis. Some factors in this journey have been shown to vary markedly across healthcare infrastructures in Europe [7]. For example, the delay of patients in seeking medical advice was an important factor in the UK [8], whereas the initial healthcare professional delay was significantly longer than the patient delay in Germany [7]. Therefore, the health environment, including the healthcare delivery system of the country, should be considered when investigating factors related to diagnosis delay. In addition, recent reports suggested that causes of treatment delay in early RA differ according to patient autoantibody status [9].

In order to identify factors related to delayed diagnosis of RA and thus facilitate early diagnosis, it would be helpful to determine the sociodemographic or clinical factors influencing recognition of this disease.

In this study, we aimed to identify factors associated with time to diagnosis after symptom onset in patients with early RA.

The average delay in the assessment of patients with RA by rheumatologists in Korea was 1.89 years. This delay in RA diagnosis was longer than that reported across Europe (from 16 weeks in Austria to 38 weeks in Greece) [7], but shorter than that in Saudi Arabia (30 months) [11]. Our study suggested that old age at symptom onset, higher education level or income, and initial small joint involvement were factors associated with shorter time to diagnosis in early RA patients.

In Korea, the time lag between the patient seeking medical advice and a rheumatologist seeing the patient is typically not long. In the Korean healthcare delivery system, the patients have freedom of choice and can go to any doctor or any medical institution, including any hospital that they choose. Furthermore, all people in South Korea are eligible for coverage under the National Health Insurance Program [12]. Therefore, the main component of delayed diagnosis in Korea may be patient-dependent. Based on the results of our study, patients with younger onset age and without involvement of the small joints are more likely to have a delay in RA diagnosis. This may be related to public communication and education regarding typical RA symptoms. The factors related to RA disease process were consistent with previous reports [13,14]. There is controversy over the relationship between presence of autoantibody in patients and delayed RA diagnosis. In our study, positivity of RF or ACPA was not related to early diagnosis. However, a previous report suggested the significance of RF for early diagnosis [14] and in a recent report, positivity of RF and positivity of ACPA were both associated with a significant delay in initiation of DMARDs [9]. In addition, delayed diagnosis can result from the fact that identification and diagnosis of RA is difficult due to the insidious nature of the disease and the widespread use of non-steroidal anti-inflammatory drugs, which have the potential to mask RA symptoms.

An American College of Rheumatology-European League Against Rheumatism (ACR-EULAR) task force suggested that delays to diagnosis and starting treatment include four main stages: (1) from symptom onset in patient to assessment in primary care; (2) from primary care provider to rheumatology referral; (3) from rheumatology referral to assessment; and (4) from rheumatology assessment to commencement of DMARDs therapy [6]. Previous systematic literature reviews showed various efforts at addressing referral delays [6]. For the first two steps, internet and website information based on patient self-administered questionnaires to recognize patients with possible inflammatory arthritis were included [14-16]. The data in a previous report were restricted to Europe and North America. In Korea we also established an internet website (www.rheusearch.com) based on a self-administered early inflammatory arthritis detection tool [15] adapted to the Korean language, thus allowing the patient to evaluate the possibility of early inflammatory arthritis by themselves. This guide may improve the accessibility of patients with inflammatory arthritis to a rheumatologist and help to lead to early diagnosis of rheumatic diseases in Korea.

Early diagnosis of RA is associated with decreased radiologic progression or functional disability [4,17]. In our study, the frequency of hand joint erosion was lower in the early diagnosis group than in the late diagnosis group, although their disease durations were similar.

Our study has some limitations. First, our data cannot separate the delay in the time from symptom onset to seeing the primary physician and the time from visiting the primary physician to seeing a rheumatologist. Therefore, we cannot determine the delay period associated with primary physician referral to a specialist. However, it is more important to improve the early detection of inflammatory arthritis in the patients’ perspective in Korea because patients feeling pain in their joints can see a rheumatologist in the primary care setting in the Korean health environment. Second, the reported symptom onset date might be inaccurate because of recall bias. To avoid this bias, we extracted early RA patients who were enrolled within 1 year from RA diagnosis. Third, it is possible that not all factors influencing the delay in RA diagnosis were included in this analysis. However, our finding of patient factors associated with delayed diagnosis can be important to generate a strategy for the first delay step from symptom onset to assessment in primary care.

The findings of our study are noteworthy in several ways. First, the reported delay in RA diagnosis was also present in Korea, which is known to have good healthcare access. Second, we found that patients with low educational level, young age or initial involvement of the large joints are at high risk for delayed diagnosis of RA. This result implies that we have focused on patients with typical characteristics or symptoms of RA to date. However, it needs to focus for the education of young patients and primary physicians.

In conclusion, we identified a delay in RA diagnosis in Korea, consistent with findings from various regions around the world. Older age at symptom onset, higher education level or income, and initial involvement of the small joints were factors associated with a shorter time to diagnosis in early RA patients. Our efforts to improve the accessibility of patients with inflammatory arthritis to rheumatologists could accelerate early RA diagnosis.