Researchers enrolled 472 patients in a randomized clinical trial. Patients were randomized to undergo diskectomy (n = 232) or nonoperative treatment (n = 240), which included physical therapy, education/counselling with home exercise instruction, and nonsteroidal anti-inflammatory drugs, if tolerated. There was follow-up at 6 weeks, 3 months, 6 months, and 1 and 2 years.

The researchers found that adherence to assigned treatment was limited: 50 percent of patients assigned to surgery received surgery within 3 months of enrolment, while 30 percent of those assigned to nonoperative treatment received surgery in the same period. Intent-to-treat analyses (in which group outcomes were assessed based on the therapy to which the patient was initially assigned) demonstrated substantial improvements for all primary (pain and physical function measures) and secondary outcomes (sciatica severity, satisfaction with symptoms, self-reported improvement, and employment status) in both treatment groups. The intent-to-treat analysis likely under represents the true treatment effect, while the as-treated analysis likely overestimates the true treatment effect.

"Patients in both the surgery and nonoperative treatment groups improved substantially over the first 2 years," the authors write. "Between-group differences in improvements were consistently in favour of surgery for all outcomes and at all time periods but were small and not statistically significant except for the secondary measures of sciatica severity and self-rated improvement. Because of the high numbers of patients who crossed over in both directions, conclusions about the superiority or equivalence of the treatments are not warranted based on the intent-to-treat analysis alone."; Source: American Medical Association