Forty patients were invited, of which 16 participated. Reasons for non-participation included time constraints, low motivation, and the presence of restricting comorbidities. Participating patients had a mean age of 57.4 (SD 13.3) years, mean symptom duration of 26.8 (SD 17.4, range 3–64) years, and mean ASDAS of 3.0 (SD 0.5) (Table 1). The 11 included rheumatologists had a mean work experience of 16.7 (SD 10.6) years, and 7 (63.6%) worked in a university hospital. A total of 23 patient cases were discussed with the rheumatologists (1–4 patients each): the 16 interviewed patients and seven additional non-participating patients. The characteristics of patients in both groups were largely comparable. Fifteen of the 23 (65.2%) patients discussed were being treated with a biological disease-modifying anti-rheumatic drug (bDMARD) at the time of the consultation with no treatment adjustments made.

Table 1 Characteristics of the participating patients and rheumatologists

A non-exhaustive sample of illustrative quotes per identified theme is presented in Table 2 (qualitative component). Survey results from patients and rheumatologists are presented in Figs. 1 and 2, respectively (quantitative component).

Table 2 Illustrative quotes from patients and rheumatologistsFig. 1

Results of the supplementary survey for patients (n = 16). NA: not applicable

Fig. 2

Results of the supplementary survey for rheumatologists (n = 11). ASDAS: Axial Spondyloarthritis Disease Activity Score; axSpA: axial spondyloarthritis; T2T: treat-to-target

Barriers to T2T

Four themes pertaining to barriers were identified. In patients where the rheumatologist found the ASDAS to be falsely elevated and therefore not an indication to intensify treatment, inaccuracies in disease activity measurement was a prominent theme. Conversely, in patients where the rheumatologist agreed with the ASDAS indicating active disease and considered treatment adaptations, obstruction by patient-related factors or the limited treatment options and evidence available to support a T2T strategy in axSpA were highlighted. In addition, logistical challenges was a theme applicable to both subgroups.

Disease activity measurement

Challenges in accurately measuring disease activity using the ASDAS were emphasised. Particularly, numerous patients reported both during the interviews and in the survey (n = 10/16, 62.5%) that their input on disease activity questionnaires was often influenced by comorbidities with overlapping symptoms (Quote P1). This resulted in frequent discrepancies between the ASDAS and the rheumatologist’s clinical impression, instilling doubts on the ability of the ASDAS to discern inflammatory from non-inflammatory symptoms and provide sufficient insight into actual disease activity (n = 8/11, 72.7%) (Quote R1). Considering that non-inflammatory comorbidities, such as pain sensitisation syndromes, may present with symptoms that resemble axSpA manifestations (e.g. enthesitis-like symptoms), it was mentioned that using scoring instruments to make this differentiation is particularly challenging in patients with axSpA. To illustrate the magnitude of some of these discrepancies, in certain cases, a de-escalation of therapy was even considered despite an ASDAS indicating active disease due to the absence of inflammatory symptoms on clinical examination. This also relates to concerns expressed by rheumatologists in the survey on the established cut-off values (n = 10/11, 90.9%). Therefore, even though rheumatologists acknowledged the value of using (individual components of) the ASDAS for longitudinal monitoring and to aid treatment decisions (n = 8/11, 72.7%), especially in the early stages of disease management, achieving a low ASDAS was rarely the sole treatment target pursued for the patients discussed (Quote R2). Rheumatologists preferred to base decisions on their own clinical judgement instead (derived from the patients’ history, physical examination, and laboratory and imaging results), and were reluctant to intensify treatment in the absence of objective manifestations or if a plausible alternative aetiology for the symptoms was present.

An additional consideration was the temporal context of disease activity measurements. Patients reported experiencing frequent fluctuations in symptoms, making single ASDAS measurements not reflective of their overall condition. Furthermore, rheumatologists believed that treatment intensification would have been premature in patients who had recently started new drugs or were awaiting further diagnostics.

Patient-related factors

The personal circumstances of patients were frequently central to the decision by rheumatologists to not intensify treatment (n = 8/11, 72.7%). A common sentiment amongst patients was satisfaction with the status quo and the wish to continue with their existing treatment regimens (Quotes P2 and P3). As reflected by patients both during the interviews and in the survey, there was also concern about switching drugs, for instance due to previous negative experiences with treatment adaptations, doubts about the effectiveness of other drugs (n = 4/16, 25.0%), or fear of side effects of new drugs (n = 5/16, 31.3%) (Quote P4). Finally, patients often believed that axSpA flares were temporary and self-limiting (n = 12/16, 75.0%), making treatment intensification unwarranted (Quote P5). Overall, the majority (n = 13/16, 81.3%) of patients had no desire for treatment adaptations, some of whom expressed a definitive objection. Instead, several stated the preference for analgesics or non-pharmacological interventions to sustain an acceptable symptom state (Quote P6). In such scenarios, rheumatologists were inclined to follow the patient’s lead, provided that the risks of forgoing treatment intensification were acceptable (Quote R3).

Another obstacle was patients’ limited knowledge on the rationale of the T2T strategy and treatment goals. Rheumatologists noted that these topics were rarely discussed explicitly during consultations, and experienced challenges in educating patients on these aspects, particularly in the early stages of disease management when patients might feel overwhelmed (Quote R4). Additionally, patients with underlying learning disabilities or psychiatric comorbidities sometimes had difficulty understanding, or were less receptive to, new treatment-related explanations and instructions. As such, some patients– especially those who considered their symptoms acceptable despite an elevated ASDAS– found tight control unnecessary. Having infrequent follow-up appointments, combined with the possibility to contact the outpatient clinic if needed in-between, was perceived as sufficient by them (Quote P7).

Finally, objective health-related factors, such as drug intolerances, complicated the disease management of some patients and limited the execution of a T2T strategy as well (Quote R5).

Limited treatment options and evidence

The limited number of pharmacological treatment options available for axSpA was emphasised by rheumatologists, which led to reluctance to rapidly cycle between different drugs to avoid exhausting all alternatives (Quote R6). As highlighted both during the interviews and in the survey, limited evidence available to support a T2T strategy in axSpA further reinforced this reluctance (n = 10/11, 90.9%), as well as scepticism about the benefits of aggressive treatment on patient outcomes (n = 8/11, 72.7%). Based on their previous experiences in treating axSpA, rheumatologists did not believe that deviating from T2T recommendations would necessarily lead to undertreatment or poorer outcomes (Quote R7).

Logistical challenges

Rheumatologists reflected that time pressure and capacity shortages at the outpatient clinic led to inability to consistently apply all components of T2T, such as the regular evaluation of specific treatment goals (Quote R8). This is consistent with the survey, where rheumatologists expressed doubts on the applicability (n = 6/11, 54.5%), feasibility (n = 8/11, 72.7%) and flexibility (n = 7/11, 63.6%) of a T2T strategy in practice. Additionally, rheumatologists found their current electronic medical records (EMRs) unsuitable for the longitudinal monitoring of disease activity scores and the recording and tracking of treatment goals (Quote R9). Applying a T2T strategy was, therefore, not embedded in the routines of rheumatologists, and the majority expressed low motivation to do so (n = 6/11, 54.5%). Finally, one patient who was under treatment by multiple specialists (due to the presence of extra-musculoskeletal manifestations) found that care was not always well-coordinated, leading to difficulties in adapting treatment plans (Quote P8).

Facilitators of T2T

Three themes pertaining to facilitators were identified, relating to patients’ knowledge about axSpA and rheumatologists’ awareness of the T2T strategy, positive doctor-patient relationships, and availability of a supporting infrastructure at the outpatient clinic.

Knowledge and awareness

Patients expressed having broad knowledge about axSpA, particularly on manifestations indicating active disease, enabling constructive discussions between patients and their healthcare providers (Quote P9). This insight was facilitated by explanations provided by healthcare providers (often shortly after diagnosis) and the proactive attitude demonstrated by certain patients.

Rheumatologists were largely familiar with T2T recommendations (high awareness: 45.5% [n = 5/11], moderate awareness: 54.5% [n = 6/11]), and the majority had trust in its developers (n = 8/11, 72.7%). Consistent with T2T recommendations, all rheumatologists strived for clinically inactive disease in their patients (albeit not necessarily according to the ASDAS), with attention for quality of life in particular.

Doctor-patient relationships

The robust collaboration between patients and rheumatologists was underscored. Patients experienced high involvement of rheumatologists in their care and trusted their expertise. This translated into willingness to follow their rheumatologist’s advice, as long as sufficient justification was provided. Particularly, patients viewed compliance with professional advice as being in their own interest, and were therefore open to tight(er) control if deemed medically necessary (Quote P10).

In addition, positive doctor-patient relationships facilitated constructive SDM. While rheumatologists reflected that not all patients were equipped or motivated to actively participate in SDM, it was still considered a necessary component of consultations (e.g. to provide explanations and discuss patient opinions) (Quote R10). Likewise, patients indicated a widespread preference for SDM over a paternalistic approach, albeit guided by the rheumatologist’s expertise (Quote P11). In practice, both patients and rheumatologists felt that SDM had been well-implemented, which in turn contributed to further strengthening of doctor-patient relationships with time, and reassured patients that their personal concerns were taken seriously (Quote P12).

Finally, one rheumatologist highlighted collaboration with informal caregivers in the SDM process as a pivotal supporting factor, particularly to encourage compliance (Quote R11).

Supporting infrastructure

Certain modalities available for disease monitoring were emphasised as beneficial. Patients highly appreciated having continuity of care and the ability to contact the outpatient clinic between consultations. Additionally, some patients recognised the benefits of using disease activity questionnaires as an assisting tool, provided they were addressed during consultations. While it was mentioned during the interviews that scores were frequently biased and therefore required contextualisation with the patient’s history (as highlighted in the theme ‘Disease activity measurement’), patients expressed in the survey that these instruments were, to a certain extent, still reflective of their current condition (n = 12/16, 75.0%). Finally, the availability of digital resources and possibility for consultations with rheumatology nurses to offer further guidance on the use of anti-inflammatory drugs, non-pharmacological therapies, and lifestyle was valued (Quote P13).