[Evaluation of the surgical process for herniated lumbar disk. II. Approximation to scientific-technical quality]

The procedure of surgical treatment of lumbar disc herniation belongs to the group of clinical practice procedures that have a great repercussion on health care systems. The high prevalence of this disease, the management variability and the possibility of improvement, explain the great interest in the evaluation of the quality of both treatment procedure and outcomes.

To determine and analyze the scientific and technical quality (STQ) of lumbar disc disease surgery and its correlation with some outcome measurements (clinical efficacy-functional grade and quality of life).

172 patients who underwent a hemilaminectomy for lumbar herniated disc between 1996 and 1999 were studied. To analyze the STQ, we used the PEP (Performance Evaluation Procedure) method. A modification of Spangfort's criteria: to measure the functional grade- and the 12-item Short-form health survey (SF-12) to measure the quality of life- were the methods used to quantify outcomes, assessed after 12, 24 and 36 months after surgery.

The mean overall STQ score was 0.83 (0-1). The anamnesis was the stage with worse information quality. Though neurosurgeons usually consider the anamnesis and physical examination data as the most important factors for decision making, these were no the best collected in the clinical reports. Surprisingly, data considered not relevant by neurosurgeons were registered with higher fidelity. An statistically significant correlation was found between STQ score and employment status among other parameters associated to the quality of life. The highest STQ scores were found in patients who did not return to work because of persistent pain 12 or 24 months after surgery (p < 0.02 and p < 0.04) and in patients showing poor social interaction and severe pain 12 months after surgery. When analyzing the completeness of clinical history data, statistically significant differences were observed in relation to the type of employment and the degree of physical effort needed at work. Patients working in positions without high skill requirements (p < 0.002) and involving a great physical effort (p < 0.05) had better registered data. Patients with better registered information tended to show a lesser clear surgical indication as a common characteristic, i.e., negative straight leg raising test, length of the current episode lasting more than 6 months and absence of symptoms (p < 0.01) for more than one year since the initial visit to the physician from the beginning of symptoms (p < 0.01), etc.

This method established a significant correlation between STQ and clinical and presurgical variables, as well as between STQ and pain and activity after surgery.