Spondyloarthritidies (SpA) constitute a group of chronic inflammatory diseases character of unknown etiology associated with the HLA B27 histocompatibility antigen, with ankylosing spondylitis (AS) being representative of them.1,2 The essential clinical feature in most patients is the sacroiliac joint inflammation in the early stages of the disease, although this may coincide, or be added in the progression of the disease and be preceded by inflammation in the rest of the axial skeleton and peripheral structures such as joints and enthesis.3 They may be associated with inflammatory bowel disease (IBD), skin psoriasis, and extra-articular manifestations such as anterior uveitis (AU).4–6

Definitive diagnosis of SpA (once established) is relatively simple.7–9 It is difficult to establish a diagnosis in the initial stages of the disease. However, for clinical-therapeutic purposes it is important to reach a diagnosis as soon as possible to establish an effective treatment for preventing the development of functional limitation or structural10 damage.

In Spain the average delay between onset of symptoms and diagnosis of SpA is more than 6 years.11 This may be due in part to the fact that classification criteria contemplate late appearing signs, such as radiological damage. For this reason, new classification criteria have recently been proposed,12,13 which allow us to identify such patients early. Another reason that could explain the delay in diagnosis is that primary care physicians (PCP) are not familiar with the symptoms of the disease in its early stages, when it is also called a prerradiologic phase of the disease. It is a proven fact that the early identification of the initial symptoms and referral to a rheumatologist contributes to early diagnosis of SpA.14 That is why the Spanish Society of Rheumatology (SER) developed in collaboration with PCP the Esperanza15 Program,16 in which referral criteria for patients suspected of SpA from primary care to rheumatology were established.

The objective of this study is to assess the degree of agreement between PCPs and rheumatologists in the evaluation of the criteria for referral of patients with suspected early SpA. This will optimize, if necessary, the training for PCP in SpA, which can translate into a decrease in delayed diagnosis and optimization of available resources.

The Esperanza Program involved 1844 PCP that led filled data into the electronic platform used for this purpose, with a total of 1179 patients entered (both good/poor referrals and those with a final diagnosis of SpA), with most patients being male (54%), white (96%), with a mean age of 33 years (SD 7 years), with 12% in a situation of temporary work disability and 2% in a situation of permanent disability.

Finally, for the purposes of this study we have analyzed data from 802 patients (about 70% of the total sample); we excluded poor referrals not meeting inclusion criteria or without enough data were available. Only in 98 cases (8.31%) we considered that the patient was a poor referral. Furthermore, the average time between referral from primary care and review by the UESP was 11 days (SD 28 days).

Kappa (k) scores obtained are shown in Table 3, along with the number of patients for which the estimate was made. Regarding the referral criteria with more weight at the time of diagnosis of SpA, inflammatory back pain showed a poor level of agreement (k=0.162, 95% CI 0.09–0.23), as did radiological sacroiliitis (k=0.319, 95% CI 0.21–0.43), and joint or back pain (k=0.216, 95% CI 0.14–0.29). However, the criterion of asymmetric arthritis showed a moderate degree of agreement (k=0.513, 95% CI 0.43–0.59), as well as family history of SpA, psoriasis, IBD or AU (k=0.509, 95% CI 0.41–0.60) and the presence of positive HLA B27 (k=0.597, 95% CI 0.52–0.67).

In relation to the degree of agreement with other criteria related to the diagnosis of SpA, but with less weight, there was a degree of good or very good agreement on the following criteria: AU (k=0.81, 95% CI 0.68–0.93), IBD (k=0.877, 95% CI 0.79–0.96), and psoriasis (k=0.735, 95% CI 0.65–0.81).

The Esperanza Program was built to improve the management of patients with SpA.

It has allowed both rheumatologists and PCP to be aware of the need for early and accurate diagnosis of patients with these diseases. For this reason, among others, criteria for referral to Rheumatology were generated to serve in establishing a definitive and/or early diagnosis of SpA. The results of this analysis indicate a degree of agreement between PCP and rheumatologists regarding the evaluation of established referral criteria.

Moreover, the objective was to analyze the correlation between PCP and rheumatologists regarding patients with early SpA, not the early clinical suspicion (in general). We have not analyzed all patients referred by PCP, but inclusion of patients occurred in a random, common, daily practice, so we think that selection bias is very low and there is no overestimating the effect.

Regarding the design of the study, the observations were not independent, which in theory may overestimate the degree of agreement. However, we think this effect is in turn offset by the second evaluation and reclassification on patients once they reach the UESP, by a rheumatologist and, whose judgment was not considered to be influenced by the PCP.

Furthermore, it should be noted that radiological sacroiliitis and the presence of HLA B27 should be interpreted with caution since these results could not be analyzed in all patients.

The degree of agreement was good or very good for some of the referral criteria, in particular for the presence of UA, psoriasis and IBD. This may be because they are, a priori, clinical entities easily identified by both PCP and rheumatologists.

The degree of agreement was moderate for the presence of HLA B27, asymmetric arthritis and family history. In the case of HLA B27, not a laboratory test requested very often by primary care unlike Rheumatology, there are a few centers where this can be obtained. A very similar explanation can be given in relation to the presence of asymmetric arthritis. The rheumatologist constantly turned towards the anamnesis, symptoms and signs suggestive of inflammation, and detected very early and mildly intense arthritis, something that often is only possible after having reached a high degree of specialization, and having the necessary time to evaluate the joints of patients. In this context, we believe that the PCP can acquire the skills and knowledge needed to detect incipient arthritis cases with adequate training and education. Finally, note that a correct history in the case of family history is relevant because it is a very specific variable in this group of diseases. Increased knowledge in SpA could help include this variable in the history performed by the PCP in selected patients with suspected disease.

We should note that the results showing the lowest level of agreement was that regarding the most important referral criteria to establish the diagnosis of SpA, inflammatory back pain and radiological sacroiliitis. Diagnostic difficulty regarding inflammatory back pain in primary care has been observed,17 and possibly because low back pain is a common, but vague and poorly reported symptom, and that a large percentage of those with LBP are referred first to the orthopedic specialist instead of the rheumatologist, without delving deeper into pain characteristics. Given the large volume of patients seen by PCP and requiring clinical diagnoses, to improve these results, in the most prevalent groups with this disease, i.e. young adults, a differential diagnosis between mechanical and inflammatory back pain should be done before referring to a specialist. Probably more and specific training for PCP in this regard would be very satisfactory and sufficient.

Furthermore, in the case of the evaluation of sacroilitis, we advance the same arguments and provide ways to improve them. If there is a clinical suspicion of inflammatory back pain of possible sacroiliac origin it is easy to ask for an X-ray of these joints. And again, the training and ability of PCP reading sacroiliac radiography should not delay over 30s, and allow a high percentage of patients to have a more precise18 diagnostic orientation. Additionally, due to the lack of good agreement regarding X-rays, training activities for standardizing the reading thereof could arise as a means to optimize the results of future diagnoses of SpA.

In conclusion, based on the importance of early diagnosis and the need for optimal treatment in patients with SpA, and PCP as the first contact with the health system, targeted training in this regard could help achieve these objectives, in young patients with inflammatory LBP features, requesting a sacroiliac X-ray and performing anamnesis directed toward these pathologies.

Protection of human and animal subjects. The authors declare that no experiments were performed on humans or animals for this investigation.

Confidentiality of Data. The authors declare that they have followed the protocols of their work centre on the publication of patient data and that all the patients included in the study have received sufficient information and have given their informed consent in writing to participate in that study.

Right to privacy and informed consent. The authors have obtained the informed consent of the patients and /or subjects mentioned in the article. The author for correspondence is in possession of this document.

The authors declare that there is no conflict of interest.