Applied Evidence

Translation, cross-cultural adaptation, and measurement properties of the Back pain knowledge and beliefs survey (BacKS) for the Brazilian population.

Brazilian journal of physical therapy · 2026 · Other · PT

Leticia Amaral Corrêa, Mark J Hancock, Stephanie Mathieson and 6 others

PMID 42217509

A validated Brazilian Portuguese version of a 20-item back pain knowledge and beliefs questionnaire is now available.

It takes 6 minutes, scores from 20 to 100, and higher scores mean more evidence-based understanding. Use it to see what your patient already knows.

Key findings

1The 2-factor structure was confirmed in the Brazilian sample with good model fit after minor adjustments.

2Internal consistency was adequate (Cronbach's alpha 0.86 for the biomedical factor, 0.71 for self-care, 0.84 total) and test-retest reliability was adequate (ICC 0.92, 0.71, 0.91) in 67 stable participants.

3The smallest detectable change for the total scale is 11.09 points on a 20-to-100 range.

Still to come

How it was doneWhat they foundWhat it means for PTs


Read the rest of this summary

You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.

Already have one?

What it does not show

Most participants (87%) were from the Southeast region of Brazil, so the tool may not reflect the language and beliefs of patients in other regions. Over 70% of participants had completed tertiary education, and no one with only primary education was in the pilot, so the findings may not generalise to less educated patients. Only 67 participants completed the test-retest after those who received pain education in the interim were excluded, giving wide confidence intervals. Scalar invariance between the Brazilian and Australian versions was not fully confirmed, so direct score comparisons between the two countries carry some risk of response bias. The smallest detectable change is higher than in the Australian sample, so a change that looks meaningful in an Australian study may be within measurement error here. No intervention was applied, so the tool's ability to detect real change (responsiveness) and the minimal important change were not assessed.

Declared interests

None declared.

The easy way to misread this

Do not assume the test-retest reliability is as precise as the Australian version. Only 67 participants completed the follow-up after those who received pain education were excluded, and the smallest detectable change is higher than in the Australian sample.

Summarised by AI from the full paper, without a clinician reviewing it. Check it against the source before it changes what you do. Read it on PubMed →