In this study, we have developed an easy to use questionnaire to assess barriers and facilitators to PA for patients with IA. The proposed IFAB questionnaire has 10 items, with a score from − 70 to 70, higher scores indicating higher levels of facilitation and lower levels of barriers. This questionnaire appears to be feasible, reliable and to have satisfactory internal consistency. This questionnaire may guide targeted interventions to increase PA level of patients with IA.
This study has strengths and weaknesses. The generation of themes was based on a systematic literature review of barriers and facilitators to PA for patients; however the review concerned RA only, due to the more extensive literature in this population. Recently, similar barriers and facilitators have been evidenced in patients with AxSpA  and to our knowledge barriers and facilitators to PA have not been studied in patients with PsA. Cognitive debriefing was applied to improve the understandability of items by patients. Cognitive debriefing is an important step and generally under-used . The development process of the questionnaire involved a variety of experts, including physiotherapists, which is rarely the case. The assessment of psychometric properties was complete, including internal consistency, construct validity, data completeness and reliability . Many questionnaires applied in rheumatology have not undertaken such a complete psychometric assessment . The sample size of patients to assess the validity of the questionnaire (n = 63) was low but is considered by COSMIN as adequate . The sample size for reliability may be considered as low (n = 32) . However, proper statistical analysis was used (ICC) and reliability was satisfactory . No analysis of differential effect in different diseases was carried out. However, all the 3 IA diseases were represented and levels of pain and functional status were equivalent among IA diseases (data not shown). The absence of correlation between the IFAB and questionnaires assessing fear avoidance/beliefs about PA and kinesiophobia was unexpected. However, the IFAB questionnaire assesses several dimensions and some of these are not related to fears (avoidance or kinesiophobia), such as social support or level of symptoms. We believe the global nature of the IFAB could explain the lack of correlations. Furthermore, construct validity showed some correlation with functional status, which was expected and strengthens the face validity of the IFAB questionnaire.
Other questionnaires have been developed to assess barriers to PA in the general population  or other disabled populations such as osteoarthritis , mobility impairments , stroke population  or coronary artery disease . In these questionnaires, the number of items used to assess barriers varied from 11 to 63. Only one recently-published questionnaire (the EPPA questionnaire) assessed facilitators of PA . Seven out of ten barriers and facilitators of the EPPA questionnaire were also assessed in the IFAB questionnaire, indicating an expected overlap. However, the EPPA questionnaire is applicable to osteoarthritis, not IA. When comparing with a theoretical framework of behaviour change developed by Canes in 2012, we observed that the IFAB questionnaire covers 7 out of the 14 possible domains (knowledge, beliefs about the capabilities, beliefs about consequences, reinforcement, intentions, environmental factors and resources and social influence) . This shows the potential interest of the IFAB questionnaire to examine different aspects of the areas of behaviour change.
PA is highly recommended for the IA population, but not performed sufficiently . There's been a growing interest patient reported outcomes; the Food and Drug Administration underlines their importance and encourages their use . This study applied recommended methodology for the IFAB questionnaire development and validation. The current questionnaire can be both used for research and clinical practice as it takes less than 5 minutes to complete and has little missing data. This questionnaire has the potential to identify perceptions towards PA in order to address barriers such as mistaken beliefs, and encourage facilitators. It may be useful to implement such a questionnaire during patient education to increase awareness of barriers and facilitators or in clinical trials evaluating PA level to observe the relationship between perceived facilitators and barriers and PA levels. The question remains on how to interpret IFAB scores. In the present study, the median of the score was 3 (range − 70 to 70), with a first quartile value (defining the lower 25% of the group) at -5. It might be interesting to propose a targeted intervention to patients with the lower scores, for example negative scores or scores below − 5.
Cultural environment is important to consider when assessing barriers and facilitators. Different aspects of the IFAB questionnaire, such as social environment and psychological status, can be influenced by culture and habits . The questionnaire was validated only in France. However, the systematic review performed to develop the questionnaire included studies conducted in various countries. Moreover, experts involved for the face validity came from different countries (France, Norway and England). The questionnaire was developed both in English and French following a validated translation and cross-cultural adaptation process . The culture of PA can change from country to country and from year to year . Policies and regulations vary across the world. Through national prevention plans, increasing numbers of people are aware of the recommendations to perform PA . The popularity of a sport evolves over the years as shown nowadays by the growing interest in running or fitness. Technology is more and more developed and used to promote and track PA and the image of an athletic body is more and more valued . The physical environment is also being adapted to allow regular PA, e.g. through the installation of biking lanes or recreational programs in parks. In addition, the cost of activities tends to decrease. As a consequence, it is possible that this questionnaire will have to be updated in the future.
In conclusion, this short questionnaire may be useful to assess barriers and facilitators in order to increase PA in IA patients. Further studies should assess the relation between IFAB scores and objective PA, and assess the efficacy of interventions to improve PA, based on the IFAB score. This questionnaire could be used to design intervention with bigger chance of success and to help implement physical activity recommendations.