Introduction In order to take a correct decision while qualifying for prevention programs, particularly in regard to persons with disability certificate, a detailed physiotherapeutic examination needs to be conducted. Currently practitioners are looking for methods allowing for quick assessment of patients’ health before advising prevention or treatment. This paper examines the Functional Pain Index (FPI), a tool conceived by the authors, and compares the results with the results of the anamnesis and physical examination conducted by a physiotherapist. Material and methods Sample group consisted of 206 workers with disability certificate who have been experiencing low back pain (LBP). Each person went through physiotherapeutic examination, it was concluded by a decision to either qualify them for prevention program or advise LBP treatment. This result was compared with the FPI questionnaire and qualification based on the result produced by the questionnaire. Results The FPI based on three variables embedded in the questionnaire showed no statistically significant difference compared to a similar index based on the documentation produced by physiotherapeutic examination. Following the latter, 87 persons were qualified for prevention programs, with the FPI in this group ranging on average from 31.9 to 36.8 points, depending on the applied FPI variant. 119 persons were advised physiotherapeutic treatment or medical consultation, with the FPI in this group ranging from 51.8 to 57.5 points. It has been also shown that there is a statistically significant correlation between a decision of a physiotherapist to advise LBP prevention program and the FPI score in all its variants (p<0.001). Conclusions High consistency between the FPI based on the questionnaire and the index based on physiotherapeutic examination shows that the questionnaire is highly reliable. The FPI questionnaire can be a good alternative for qualifying patients for prevention programs, with questionnaire-based qualification for prevention program triggered in 0-40% range of the FPI.