Background: Telephone surveys are being used increasingly in community-based epidemiological studies since the 1970s. They are less expensive and less time consuming for both interviewers and interviewees, with similar or even higher response rates than face-to-face interviews.

Objectives: In this study we used both telephone interview and face to face interview strategies to assess the performance of the existing criteria sets for inflammatory back pain (IBP) to examine whether telephone interview method can be used for screening for IBP in the community.

Methods: The study sample included a total of 172 patients with axial spondyloarthritis (AxSpA) all fulfilling the imaging arm of the ASAS criteria and 25 patients (mean age: 46,9±13,8 years; % 48 male) with chronic mechanical back pain according to the treating physician's judgment (control group). Of the patients with AxSpA, 58 patients (mean age: 41,5±13,3; % 25,9 male) had active sacroiliitis (SI) on MRI as defined by ASAS (preradiographic AxSpA) and 114 patients (mean age: 42,1±12,0 years; % 66,7 male) had radiographic SI as defined bythe modified New York criteria (AS group). A telephone interview by using a standardized questionnaire addressing all the components of IBP which included in Calin's, Berlin and new ASAS criteria sets was performed on all study subjects by one physician. The same physician conducted also a face to face interview by the same questionnaire. Cohen's kappa test was used to evaluate the agreement between the data collected by telephone and face to face interviews. For group comparison's Krusskall-Wallis test and for post-hoc comparisons Mann-Whitney U test was used.

Results: There were significantly more male patients (p<0,001) in the AS group. AS group (17,1±10,7 years) also had longer duration of low back pain. Age, education level, and call time were similar between the groups. Calin's criteria showed the highest sensitivity but also the lowest specificity by both methods. The sensitivity and specificity of the different criteria sets obtained by both interview methods were very similar for the Calin and the ASAS criteria whereas Berlin criteria had a lower specificity in the telephone interview method (Table 1). The results were similar in patient groups with or without radiographic sacroiliitis. The best agreement between the interview methods was obtained for the Calin's citeria (k=0.60). Among patients with symptoms of less than 10 years duration, there was a better agreement for all criteria sets, with the Kappa value for Calin's criteria reaching up to 0,80 in this group of patients.

Table 1. The sensitivity and specificity of different criteria sets for IBP by two interview methods

Conclusions: The performance of different criteria sets for IBP was similar for both telephone and face to face interview methods. This suggests that telephone interviews may be used in epidemiologic studies to asses IBP in the community. Because of its higher sensitivity, Calin's criteria set may be preferable for such surveys. However, this should be confirmed by further studies.

Disclosure of Interest: None Declared