Richard A. Deyo

Descriptive epidemiology of low-back pain and its related medical care in the united states

Accurate United States data on the prevalence of low-back pain (LBP) and its related medical care would assist health care planners, policy makers, and investigators. Data from the second National Health and Nutrition Examination Survey (NHANES II) were analyzed to provide such information. The cumulative lifetime prevalence of LBP lasting at least 2 weeks was 13.8%. In univariate analyses, important variations in prevalence were found by age, race, region, and educational status. Most persons with LBP sought care from general practitioners, with orthopaedists and chiropractors being the next most common sources of care. Sources of care, and in some cases therapy, varied among demographic subgroups. These data demonstrate substantial nonbiologic influences on the prevalence and treatment of LBP, and suggest an agenda for health services researchers.

How many days of bed rest for acute low back pain? A randomized clinical trial

Bed rest is usually recommended for acute low back pain. Although the optimal duration of bed rest is uncertain, a given prescription may directly affect the number of days lost from work or other activities. In a randomized trial, we compared the consequences of recommending two days of bed rest (Group I) with those of recommending seven days (Group II). The subjects were 203 walk-in patients with mechanical low back pain; 78 percent had acute pain (less than or equal to 30 days), and none had marked neurologic deficits. Follow-up data were obtained at three weeks (93 percent) and three months (88 percent). Although compliance with the recommendation of bed rest was variable, patients randomly assigned to Group I missed 45 percent fewer days of work than those assigned to Group II (3.1 vs. 5.6 days, P = 0.01), and no differences were observed in other functional, physiologic, or perceived outcomes. For many patients without neuromotor deficits, clinicians may be able to recommend two days of bed rest rather than longer periods, without any perceptible difference in clinical outcome. If widely applied, this policy might substantially reduce absenteeism from work and the resulting indirect costs of low back pain for both patients and employers.

Comparative validity of the sickness impact profile and shorter scales for functional assessment in low-back pain.

Several scales exist for measuring functional status in patients with low-back pain (LBP). There are few comparative data, however, to suggest which scales may perform best. We compared the Sickness Impact Profile (SIP), its major subscales, and a short index derived from the SIP (a slight modification of an index proposed by Roland) with regard to reliability, validity, and sensitivity to change. Walk-in patients with mechanical LBP (n=136) completed the entire SIP at an index visit and again 3 weeks later. The examination of individual items allowed scoring for the derivative scales. The modified Roland Scale appeared to have reliability, validity, and sensitivity that were at least as good as the overall SIP or its major subscales. Although the Roland Scale did not measure psychosocial function well, this aspect of functioning changed less over time than physical function.

Patient satisfaction with medical care for low-back pain.

Because patient satisfaction with medical care for back pain is an important outcome and may correlate with compliance or other outcomes, the authors devised a brief (9- item) satisfaction scale and demonstrated its reliability and validity. The most frequently cited source of dissatisfaction among 140 patients with mechanical low-back pain (LBP) was failure to receive an adequate explanation of the problem. Compared with patients who reported an adequate explanation, those who did not wanted more diagnostic tests, were less satisfied with their visit, and were less likely to want the same doctor again. Receiving an adequate explanation was not associated with more tests or physician time. Thus, explanation of symptoms has a high priority among patients with LBP, and this need should be explicitly acknowledged and addressed by their physicians.

Measuring physical and psychosocial function in patients with low-back pain

Techniques for assessing daily function in Patients with back pain are generally crude and limited in scope. We therefore examined a “health status” questionnaire, the Sickness Impact Profile (SIP) to assess its measurement characteristics in such patients. Eighty patients with mechanical low-back pain completed the SIP and a physical examination at a walk-in visit and again three weeks later. Test-retest reliability of the SIP was substantial. Biologic validity was confirmed by significant correlations with age, pain duration, spine flexion, straight leg raising, and pain severity. Validity of psychosocial subscales was confirmed by significant associations with patient anxiety and psychiatric problems. Scores changed in the expected directions when patients were evaluated three weeks later. The SIP is thus valid, reliable, sensitive to clinical changes, and comprehensively assesses a wide range of dysfunctions.

Early diagnostic evaluation of low back pain.

BACK PAIN ranks second only to upper respiratory tract complaints as a symptomatic reason for visits to office-based physicians,~ and seventh as a reason for visits to internists, z At least in some settings, fewer than 2% of these patients need surgery. Since an earlier rev iew) several important findings have emerged concerning the diagnostic evaluat ion of low back pain. While much of the direct cost of t reat ing pat ients who have back pain is related to diagnost ic tests, recent da ta suggest that selective pars imonious testing may be appropriate, especial ly in primary care. This conclusion has emerged as the roles of the clinical examination and plain radiography have been refined and clarified.

Lumbar spine films in primary care - Current use and effects of selective ordering criteria

Low back pain (LBP) often prompts radiography, although the diagnostic yield of lumbar spine films is low, and many radiographic abnormalities are unrelated to symptoms. Criteria have been proposed for selective x-ray use, but their value and safety are uncertain. To evaluate these criteria, the authors prospectively studied 621 walk-in patients with LBP. The yield of explanatory x-ray findings was over three times greater among patients with indications for radiography than among those without. Furthermore, an indication for x-rays existed for all patients found to have a malignancy, and for 13 of 14 patients with an identified fracture. Actual physician ordering, however, did not correspond well with the recommended indications. Application of selective criteria appears safe and may improve the yield of useful findings. It may not, however, reduce x-ray utilization from current levels without further refinement in the criteria.Low back pain (LBP) often prompts radiography, although the diagnostic yield of lumbar spine films is low, and many radiographic abnormalities are unrelated to symptoms. Criteria have been proposed for selective x-ray use, but their value and safety are uncertain. To evaluate these criteria, the authors prospectively studied 621 walk-in patients with LBP. The yield of explanatory x-ray findings was over three times greater among patients with indications for radiography than among those without. Furthermore, an indication for x-rays existed for all patients found to have a malignancy, and for 13 of 14 patients with an identified fracture. Actual physician ordering, however, did not correspond well with the recommended indications. Application of selective criteria appears safe and may improve the yield of useful findings. It may not, however, reduce x-ray utilization from current levels without further refinement in the criteria.

Studies of the Modified Somatic Perceptions Questionnaire (MSPQ) in patients with back pain. Psychometric and predictive properties

The Modified Somatic Perceptions Questionnaire (MSPQ) was designed to measure heightened somatic awareness among patients with chronic pain. It was hoped that this questionnaire would help predict therapeutic responses for back pain patients. The reliability, validity, and predictive characteristics of this scale were tested among 97 patients with chronic low-back pain enrolled in a clinical trial of transcutaneous nerve stimulation and stretching exercises. Internal consistency was good (alpha = 0.78), and correlations with the Zung depression scale and certain MMPI scales were significant. Correlations with a baseline functional scale (the Sickness Impact Profile) were stronger than those with the MMPI. Unfortunately, the MSPQ did not correlate with functional outcomes, and was only weakly associated with pain outcomes. Thus, the MSPQ appears to be reliable and valid, but the somatic perceptions it measures may have little relation to patient outcomes.

Chymopapain for herniated intervertebral disc. A methodologic analysis and an agenda for future research.

Chymopapain recently has won approval in the United States for use in chemonucleolysis of herniated intervertebral discs. New research findings will be emerging, but clinicians need criteria by which to assess new results, to evaluate the existing literature, and to strengthen future investigation. Twenty-six original articles on chemonucleolysis were reviewed according to nine criteria of validity and applicability. Common threats to validity were failure to use randomized controls, make blind outcome assessments, assure equal co-treatments, and to calculate statistical power when results were negative. Threats to applicability included wide variations and incomplete reporting of patient selection, procedure technique, and many relevant outcomes. Methods for improving these design features are suggested, and a basic study design is proposed for comparing chemonucleolysis with both surgical and conservative management techniques.