Low back pain (LBP) is a public health concern. The referral process to the Physiotherapist in Primary Health Care (PHC) should be assessed, as it improves disability and reduces the use of low-value resources, though there is a need for consolidation within SUS.

To investigate whether sociodemographic and clinical variables explain referrals to Physiotherapists working at NASF units (Expanded Family Health Center) in the Federal District. Secondarily, to characterize the referral time and frequency of resource use.

This is a 12-month retrospective cohort (2018/2019) consisting of electronic medical records of 48 individuals. Individuals with LBP who had not received treatment in the PHC in the previous six months and aged >18 years were included. Those with red flag signs, limited mobility and pregnant women were excluded. Participants were stratified into groups: G1) People without referral and assistance (n:23); G2) People referred and assisted (n:15); G3) People who sought care without referral (n:10). We adopted multinomial logistic regression with backward stepwise to investigate whether age, sex, drugs and exams prescriptions, number of exams, consultations with specialists and other interventions adequately classify the groups G1 (reference), G2 and G3. There was no collinearity, and data fit was confirmed by the Akaike criterion. The pseudo-R2 (Nagelkerke) demonstrated the weight of the variables in the model and the odds ratio (OR) was calculated with a 95% confidence interval (95%CI).

The mean age was 55 years (SD: 13 years), and 75% were women. Of the total, 21% received imaging tests and 10.5% received drug prescriptions. The mean referral time until the first Physiotherapy appointment for LBP treatment (G2) was 99.5 days. The overall average of Physiotherapy visits was 6.5 sessions/person. Gender, age, number of consultations with specialists and other interventions explained 56% of the model (R2). Compared to G1, the chance of being referred (G2) increased with increasing age (OR: 1.11 95%CI: 1.07;1.15), less number of consultations (OR: 0.26 95%CI: 0.10;0.91), less number of other interventions (OR: 0.21 95%CI: 0.05;0.91). The G3 was explained by female gender (OR: 17.1 95%CI: 3.3;88.8), age (OR: 1.24 95%CI: 1.17;1.31), and less number of consultations (OR : 0.06 95%CI: 0.11;0.39).

The time length for people with LBP to be treated after being referred to Physiotherapy was long. Age increments increased between 11% and 24% the chance of being referred and seeking care, respectively. The lower the number of consultations with specialists and other interventions, the greater the chance of being referred to Physiotherapy compared to people who are not referred. Women were 17 times more likely to seek Physiotherapy without a referral.

Our findings contribute to understanding the population profile and factors associated with referral to PHC Physiotherapists. We raise a caution note related to the delay in referral time is highlighted, which can cause deleterious clinical impacts.