REPORTING OF ACUTE LOW-BACK-PAIN IN A TELEPHONE INTERVIEW - IDENTIFICATION OF POTENTIAL BIASES

Study Design. This was a survey of 235 individuals with and 132 indivi duals without documented low back pain. Objectives. To approximate the magnitude of potential reporting biases in estimates of prevalence of and medical care use in low back pain. Summary of Background Data. Th e use of survey techniques presents several possible biases in the rep orting of acute symptoms. These biases are especially pertinent in mus culoskeletal symptoms, which often are recurrent and not life-threaten ing. Methods. Two-hundred-thirty-five patients with acute low back pai n were contacted by telephone 4-16 months after their physician visit and surveyed regarding the presence and date of back pain episodes. On e-hundred-thirty-two patients who had no functionally disabling back p ain on physician interview were interviewed. Results. Of the patients who had sought care for back pain, 21% indicated they had not had back pain when interviewed 4-16 months later. Episodes of pain that occurr ed more than 8 months before the interview tended to be recalled as oc curring more recently than they actually occurred, confirming ''forwar d telescoping'' Of the illness episode. Only 3% of the individuals wit hout functionally impairing pain reported such pain on a separate inte rview. Conclusions. Lack of recall occurs regarding acute low back pai n, usually a self-limited illness. This potential under-estimate of ba ck pain prevalence may be balanced by forward telescoping of the dale of illness occurrence.