Low-back pain. Factors of value in predicting outcome.

Two separate samples of 50 workers' compensation patients were assessed within 3 to 6 months of their first back injury and were reassessed at a mean of 13.7 months postinjury, at which time work status was also determined. A number of predictors on the first assessment then were correlated with return to work. These predictors included orthopaedic evaluations of severity and prognosis, the number of nonorganic physical signs, Minnesota Multiphasic Personality Inventory (MMPI) scales 1 and 3, age, education, proficiency in English, and the accuracy of patients' understanding of the bases for their medical condition as determined by the Schema Assessment Instrument (SAI). The SAI was the only variable to predict return to work significantly in both samples. These data point to the importance of patients' understanding of their medical condition for their prognosis.

Generalizability of WAIS-R factor structure within and between populations.

We investigated the reliability of the factor structure of the Wechsler Adult Intelligence Scale-Revised (WAIS-R). The WAIS-R subtests, as administered to 146 head-injured males, were factor analyzed. Two- and three-factor solutions were extracted that were consistent with past findings. Congruence coefficients were computed to determine degree of association between factor structures from all samples reported in the literature. All coefficients were impressive. Also, congruence coefficients based on factor structures derived from different samples within the same population were compared to coefficients based on different samples from different populations. No significant discrepancies emerged. Apparently, the slight factor structure variation that does exist is due to chance data fluctuation rather than to systematic population bias. This reflects well on the robustness of the WAIS-R factor structure.

Predictors of outcome in back surgery candidates.

This study employed a prospective design to examine the value of three demographic, three orthopaedic, and four psychometric variables as predictors of orthopaedic and rehabilitation outcome in 116 Workers' Compensation patients seriously considered for first lumbar surgery, separately for the 74 who eventually did undergo surgery, and the 42 who did not. The two groups differed only with respect to the number of Nonorganic Physical Signs, but a complex pattern of predictive relationships emerged, in which orthopaedic outcome was generally easier to predict than rehabilitation outcome. Among the demographic factors, level of English proficiency was the best predictor and correlated positively with orthopaedic outcome in both surgery and non-surgery cases and with rehabilitation outcome in non-surgery patients. The Nonorganic Physical Signs test emerged as the predictor of choice and correlated with orthopaedic outcome in both groups and with rehabilitation outcome in the non-surgery group. Scale 1 of the MMPI correlated with orthopaedic outcome in both groups and Scale 3 with both orthopaedic and rehabilitation outcome, but only in the non-surgery patients.

Do nonorganic signs help to predict the return to activity of patients with low-back pain?

The value of the nonorganic signs in predicting return to activity following an initial episode of low-back pain was determined. One hundred and twenty patients were assessed within 6 months of the onset of their first episode of disabling low-back pain and again at a mean of 15.3 months following injury. No correlation was found between the presence of nonorganic signs at initial assessment and either return to activity or resolution of the patient's symptoms.

Physiological changes after biofeedback and relaxation training for multiple-pain tension-headache patients.

This paper is concerned with the psychophysiology of "muscle-contraction" headaches in a group of Compensation patients suffering from multiple pain problems in addition to headaches. A total of 55 of these patients were divided into 4 groups which received frontalis EMG biofeedback, relaxation training, combined biofeedback-relaxation training, or no treatment. Differences were observed among the 3 experimental treatments and the control group with respect to headache changes, but there were no differences among groups with respect to the changes observed in four underlying physiological responses as a function of time or practice. While the subjects who showed the largest changes in headache characteristics were those who exhibited the largest decreases in frontalis EMG, these were also the subjects whose initial frontalis EMG levels were the highest. It is concluded that, in keeping with a growing literature, the link between frontalis EMG and "muscle-contraction" headaches is a tenuous one and that the changes brought about in headache symptomatology through biofeedback or relaxation training are most likely attributable to a generalization of feelings of mastery over the environment or of self-efficacy brought about in the subjects through apparent success at the task.

Muscle-contraction headaches in multiple-pain patients: treatment under worsening baseline conditions.

A total of 55 muscle-contraction headache patients were divided into four groups which received frontalis EMG biofeedback, relaxation training, combined biofeedback-relaxation training, or no-treatment control. All patients were compensation patients undergoing assessment and brought to a high level of activity for the first time since going into chronicity. In all cases, onset or aggravation of the headaches coincided with the compensation-related injury. All treatment modalities led to significant but similar levels of improvement in headaches, while the control group worsened.

A prospective investigation into the orthopaedic and psychologic predictors of outcome of first lumbar surgery following industrial injury.

One hundred sixteen patients randomly selected by officers (authors excluded) of the Workers' Compensation Board of Ontario were studied over a 3-year period. The selection criteria used were no previous back surgery and first back operation now scheduled. The purpose was to establish a battery of clinical and psychologic tests to be used in arriving at a prognosis for preoperative patients. The tests included orthopaedic examination, 10-minute Hendler questionnaire, nonorganic component assessment, psychologic interview, Minnesota Multiphasic Personality Inventory, pain drawing, locus of control, McGill Pain Questionnaire. The most striking of the many computer results obtained was an 82% prognosis success rate. The five predictor variables that most significantly predicted outcome were English proficiency, the nonorganic signs test, back pain versus leg pain, hypochondriasis scale of the MMPI, and the pain drawing.