MMPI scale 3 as a predictor of back injury report: what does it tell us?

Items and selected subscales of Scale 3 (Hysteria) of the MMPI were examined to pinpoint personality or emotional factors predictive of back injury reports in an industrial setting. Data were derived from a previous prospective-design study of back pain in volunteer hourly wage employees of an aircraft manufacturing company. After physical examination and completion of questionnaires pertaining to demographic, psychosocial (including the MMPI), and workplace factors, workers were followed for an average of 3 years. Those who subsequently reported back injury were compared with those who did not. In that study three variables predicted report of back injury, one of which was Scale 3 of the MMPI. Individual items, Ornduff et al. subscales of Psychological Denial and Body Concern, and the five Harris-Lingoes (1955) subscales of Scale 3 were analyzed. Three Harris-Lingoes subscales showed significant relationships to the criterion. Hy-3: Lassitude/Malaise; Hy-1: Denial of Social Anxiety; and, marginally, Hy-2: Need for Affection, significantly contributed to prediction effectiveness. Results and implications for the understanding of factors predicting back injury reports and for the medical evaluation of pain and the concept of pain are discussed.

Morbidity and mortality in association with operations on the lumbar spine. The influence of age, diagnosis, and procedure.

We examined the rates of postoperative complications and mortality, as recorded in a hospital discharge registry for the State of Washington for the years 1986 through 1988, for patients who had had an operation on the lumbar spine. When patients who had had a malignant lesion, infection, or fracture are excluded, there were 18,122 hospitalizations for procedures on the lumbar spine, 84 per cent of which involved a herniated disc or spinal stenosis. The rates of morbidity and mortality during hospitalization, as well as the hospital charges, increased with the ages of the patients. The rate of complications was 18 per cent for patients who were seventy-five years or older. Nearly 7 per cent of patients who were seventy-five years old or more were discharged to nursing homes. Complications were most frequent among patients who had spinal stenosis, but multivariate analysis suggested that the complications associated with procedures for this condition were primarily related to the patient's age and the type of procedure. Complications, length of hospitalization, and charges were higher for patients who had had a spinal arthrodesis than for those who had not. Over-all, operations for conditions other than a herniated disc were associated with more complications and greater use of resources, particularly when arthrodesis was performed, than were operations for removal of a herniated disc. No data on symptoms or functional results were available.

Perils, pitfalls, and accomplishments of guidelines for treatment of back problems.

Science should be the basis for guidelines. As a result of the Flexner Report in 1911, we now live in an era where randomized trials are available. Statistical methods can truly be applied to evaluate the reliability of data published in the literature. The result is that we can now demand more from future publications and allow for a better evaluation of the mistakes or bias that can distort validity, applicability, and reliability. The importance of this methodology is to reduce misunderstandings by patients, clinicians, manufacturers, and government agencies about issues important to patient care.

Paying doctors more: use of musculoskeletal specialists and increased physician pay to decrease workers' compensation costs.

Previous studies evaluating workers' compensation care systems used retrospective controls. We performed a concurrent effectiveness study comparing a WC system that used visiting musculoskeletal specialists to assist primary care physicians with a typical discounted-fee, WC, managed-care system. In the new specialist-direct system, physicians could not profit from self-referral, but were paid 35% to 69% more per patient visit than doctors in the discounted-fee clinics. All claims filed by all employees of two hotels for 2 years were examined. Patients had self-selected either a specialist-direct or a discounted-fee clinic, and the entire cost of the claim was assigned to either system of care. Claim costs were 63% lower in the specialist-direct system (P < 0.001). Medical costs were 45% less (P < 0.014), and indemnity 85% less (P < 0.001), in this system. Claims were closed nearly 6 months faster in the specialist-direct system (P < 0.0001). Indemnity claims were more common in the discounted-fee system (P < 0.0001). Claimant and injury characteristics were not significantly different between the systems. This new care model is a cost-effective alternative to discounted WC managed care. Discounting the services of the primary treating physician may result only in cost-shifting, not cost-saving.

Characteristics in Medicare beneficiaries associated with reoperation after lumbar spine surgery.

STUDY DESIGN: A cohort study was undertaken using medical claims of Medicare beneficiaries. OBJECTIVES: Factors associated with reoperation after lumbar spine surgery were identified. SUMMARY OF BACKGROUND DATA: Repeat spine surgery is one outcome measure of surgical success, but little is known about clinical or demographic factors associated with repeat surgery. METHODS: Medicare beneficiaries who had surgery in 1985 were included in follow-up through 1989. Time between the first operation and a lumbar spine reoperation, death, or end of follow-up period was recorded. Survival analysis (time-to-event) techniques were used to test the association of baseline characteristics with reoperation. RESULTS: Higher reoperation rates were associated (P < 0.05) with previous back surgery, younger age, recent hospitalization, white race, and diagnosis of herniated disc (compared with other diagnoses). Fusion alone or combined with other procedures did not lower the reoperation rate. CONCLUSION: Reoperation rates are affected not only by technical factors, but also by demographic and clinical characteristics that are often omitted from reports of surgical case series.

Back injuries in industry: a retrospective study. I. Overview and cost analysis.

To evaluate the impact off back injury on industry, the authors conducted a retrospective analysis of injuries among hourly employees of a large industrial manufacturer in western Washington. The Boeing Company provided injury information on 31,200 employees for a 15-month period from July 1, 1979 to September 30, 1980. Of the 4,645 injuries reported, 900 were back injuries. Claims related to back injuries constituted 19% of all workers' compensation claims but were responsible for 41% of the total injury costs, or approximately $1,800,000. The 90 most expensive back injury claims (10% of all back injury claims) were responsible for 79% of the total back injury costs. The percentage of back injury claimants with claims having a total incurred cost exceeding $10,000 (6.5%) was significantly higher than the corresponding percentage of claimants (1.5%) with claims for other than back injuries (P = 0.000). A similar significant difference was found concerning the tendency of back injury claimants to have multiple claims compared with the non-back injury claimants. This retrospective study reaffirms the significant economic impact of back injuries on industry, and specifically high-cost back injuries. In addition, it provides insight into factors associated with back injury and points to positive measures that may be taken to reduce back pain and economic loss. Characteristics of the back injury and employee-related factors associated with back injury are presented in two subsequent articles.

Back injuries in industry: a retrospective study. III. Employee-related factors.

To evaluate the impact of back injuries on industry, the authors conducted a retrospective analysis of injuries occurring among a group of 31,200 employees of The Boeing Company, a large industrial manufacturer in Western Washington. They analyzed 4,645 injury claims (including 900 back injuries) made by 3,958 different employees. Two previous articles give an overview of the study, provide a detailed analysis of the costs associated with these back injuries, and analyze the characteristics of the injury. This article focuses on employee-related factors associated with back injuries. Claims were categorized according to severity, as indicated by total incurred cost (TIC), the sum of the medical costs, and indemnity costs. High-cost claims were defined as those with a TIC greater than $10,000 and low-cost claims as those with a TIC less than $10,000. Employees younger than 25 years of age had a statistically significant increased risk of back injury, although their claims tended to be low-cost ones. This finding tends to discredit the premise that back problems are related to aging of the lumbar spine. While older employees had a lower injury rate, they did have a significantly increased risk of incurring high-cost back injury claims. The 31-40-year age group was the most susceptible to high-cost back injuries. Newer employees tended to have a significantly increased risk of back injury. The data show that women had fewer injuries than men but a statistically significant increased risk of becoming a high-cost injury claim.(ABSTRACT TRUNCATED AT 250 WORDS)

The load on the lumbar spine during isometric strength testing.

Reports of back discomfort and even back injuries during isometric strength testing in specific lifting positions indicated an analysis of the loads on the lumbar spine during this type of testing. A biomechanical analysis, which has been validated against EMG and intravital disc pressure measurements, was used for the calculations of the loads in four test persons. The calculations indicated compressive loads on L3 ranging from 5000-11,000 N during squat and torso lifting. Such loads in vitro have been found to cause structural failures of the vertebral endplates. Similar loads also may result in damage to the spine in vivo.

Lumbar spinal fusion. A cohort study of complications, reoperations, and resource use in the Medicare population.

Regional variations in lumbar spinal fusion rates suggest a poor consensus on surgical indications. Therefore, complications, costs, and reoperation rates were compared for elderly patients undergoing surgery with or without spinal fusion. Subjects were Medicare recipients who underwent surgery in 1985, with 4 years of subsequent follow-up. There were 27,111 eligible patients, of whom 5.6% had fusions. Mean age was 72 years. Patients undergoing fusion had a complication rate 1.9 times greater than those who had surgery without fusion. The blood transfusion rate was 5.8 times greater, nursing home placement rate 2.2 times greater, and hospital charges 1.5 times higher (all P < 0.0005). Six-week mortality was 2.0 times greater for patients undergoing fusions (P = 0.025). Reoperation rates at 4 years were no lower for patients who had fusion surgery and results were similar in most diagnostic subgroups. Indications for fusion among older patients require better definition, preferably based on outcomes from prospective controlled studies.

Back injuries in industry: a retrospective study. II. Injury factors.

To evaluate the impact of back injury on industry, the authors conducted an extensive retrospective analysis of injuries among hourly employees of The Boeing Company, the largest industrial manufacturer in western Washington. The Boeing Company provided injury information on 31,200 employees for a 15-month period from July 1, 1979 to September 30, 1980. From this information, we analyzed 4,645 injury claims filed as of February 28, 1981 by 3,958 different employees. There were 900 back injuries in this group. Claims were categorized according to total incurred cost (TIC), made up of the medical costs and indemnity costs. High-cost claims were defined as those with a TIC greater than $10,000, and low-cost claims were those with a TIC less than $10,000. Among 857 claimants with 900 back injuries, lifting or material handling was much more commonly considered the cause of injury than accidents such as slips or falls. Accidents, however, had a much greater tendency to result in an expensive claim. The authors could not make reliable conclusions regarding injuries and 32 job skill classifications. The rate of injury did not vary according to day of the week or month, but a significantly higher rate of high-cost back injuries was noted on the day shift than on the evening or night shifts.

The reliability of measurements of the lumbar spine using ultrasound B-scan.

Diagnostic ultrasound is used in research and clinical settings to determine the size of the lumbar spinal canal. When the technique was first introduced, measurements were obtained directly from an A-scan while concurrently viewing a B-scan. However, measurements obtained directly from a B-scan are now commonly used despite the undetermined reliability of the technique. To determine the reliability, 50 randomly selected ultrasound B-scan examinations were read on two separate occasions by three investigators. For each spinal level, the mean intraobserver error (same investigator), from the first to the second reading was determined, as was the interobserver error (between investigators) and the error due to variability in obtaining the ultrasound images. The resultant errors were approximately double those reported previously for the technique using A-scan. Interobserver variations were the major source of measurement error.

A prospective evaluation of preemployment screening methods for acute industrial back pain.

Preemployment screening methods have been ineffective in predicting those at risk, and in curbing the impact of back problems in industry. Such methods have centered on individual physical factors (capacities and clinical examination). This study evaluates commonly used physical examination measures and simple historical data for its ability to predict individuals at risk for future back injury reporting in the aircraft industry. In this study, once simple historical information about previous pain treatment was known, information gained from physical factors added no significant predictive value.

A prospective study of work perceptions and psychosocial factors affecting the report of back injury.

A longitudinal, prospective study was conducted on 3,020 aircraft employees to identify risk factors for reporting acute back pain at work. The premorbid data included individual physical, psychosocial, and workplace factors. During slightly more than 4 years of follow-up, 279 subjects reported back problems. Other than a history of current or recent back problems, the factors found to be most predictive of subsequent reports in a multivariate model were work perceptions and certain psychosocial responses identified on the Minnesota Multiphasic Personality Inventory (MMPI). Subjects who stated that they "hardly ever" enjoyed their job tasks were 2.5 times more likely to report a back injury (P = 0.0001) than subjects who "almost always" enjoyed their job tasks. The quintile of subjects scoring highest on Scale-3 (Hy) of the MMPI were 2.0 times more likely to report a back injury (P = 0.0001) than subjects with the lowest scores. The multivariate model, including job task enjoyment, MMPI Scale-3, and history of back treatment, revealed that subjects in the highest risk group had 3.3 times the number of reports in the lowest risk group. These findings emphasize the importance of adopting a broader approach to the multifaceted problem of back complaints in industry and help explain why past prevention efforts focusing on purely physical factors have been unsuccessful.

The role of spinal flexibility in back pain complaints within industry. A prospective study.

Commonly used clinical measurements of spinal flexibility in the sagittal and frontal planes were examined as predictors of future back pain reports within industry. The study sample consisted of 3,020 aircraft manufacturing employees who were examined and tracked for more than 4 years for reports of back pain. Modified Schober, sit-and-reach, and lateral bending measurements were not significantly associated with risk of future back pain reporting, nor were any trends present. There was a statistically significant relationship between decreased flexibility and reports of current or previous back problems. However, the differences in flexibility between subjects with and without a history of back problems were too small to be of practical significance.

Isometric lifting strength as a predictor of industrial back pain reports.

The objective of our investigation was to study isometric lifting strength in a population of industrial workers who perform a great variety of manual tasks, and to determine whether isometric strength is predictive of future back problems in such a population. Of 3,020 study subjects, 2,178 (72%) underwent strength testing in three standard lifting positions. During a 4-year follow-up period, 172 subjects tested reported back problems. When examining each isometric lift separately as a predictor of industrial back pain reports, those with greater isometric strength were at significantly greater risk than were weaker workers. However, after controlling for the effects of age, only a slight trend remained. For the blue collar workers in this study, isometric lifting strength testing was ineffective in identifying individuals at risk for industrial back problems.

A prospective study of the role of cardiovascular risk factors and fitness in industrial back pain complaints.

The authors conducted a prospective study of risk factors for industrial back pain complaints among 3,020 aircraft manufacturing employees. The study subjects completed a cardiovascular risk questionnaire, and were asked about their smoking status and past medical history, including previous back problems. Premorbid submaximal treadmill testing to predict maximum oxygen uptake (Vo2max) was completed in 2,434 subjects who were not excluded from testing due to cardiovascular risk screening. During several years of subsequent follow-up, 279 subjects reported back problems. Those who reported smoking at the time of the premorbid examination were significantly more likely to report a subsequent back problem than nonsmokers (P = 0.002). When controlling for sex and age, cardiovascular fitness, as measured through VO2max, was not predictive of future back injury reports (P = 0.26).

Spinal flexibility and individual factors that influence it.

We conducted an investigation to examine the spinal flexibility of a large, adult population and to study the effects of other individual physical characteristics on spinal range of motion. The study group consisted of 3,020 blue collar employees (2,350 men and 670 women) who underwent a physical examination that included assessments of standing and sitting height, weight, shoulder flexibility, and spinal flexibility in the sagittal and frontal planes. Flexibility measures were correlated positively to one another; however, lumbosacral flexion measurements assessed by the modified Schober method correlated to the other flexibility measurements to a much lesser degree. Age, sex, and height affected ROM, as did obesity and the ratio of standing height to sitting height. The study findings indicate that spinal ROM covers a wide spectrum of values and is affected by many individual factors. Any attempts to determine what is normal, excessive, or diminished must take into account variations caused by age, sex, and other physical attributes.

Practitioner's guide to industrial back problems.

If return to work is part of the expected outcome, more and more data indicate that medical care alone does not hold the key to providing success. Our modern physical treatments may seem a humane alternative to no treatment, but they have not been proven to significantly alter the natural course of back problems. Even the results of strongly indicated surgical treatment differ little from doing nothing at all after a 4-year period. From the physical standpoint, activation has the best track record for recovery and can be simply provided in a manner that can be used lifelong. The real key to return to work goes beyond the physical treatment by addressing the predicament of what the patient will do until age 65. This humane approach to care has evolved from common frustrations of dealing with patients with back problems, observations in the third world, and information gained from scientific studies. Medical pain, and physical models alone are unsuccessful. To be humane and successful, we can no longer ignore the nonphysical factors that can, and do, influence patients' responses to physical treatment, especially when return to work is part of the expected outcome.

Industrial back pain complaints. A broader perspective.

Industry has looked to medicine for assistance in developing screening and prevention programs to reduce the problem of industrial back injuries. Unfortunately, little is known about the pathology underlying most back symptoms, and few risk factors for industrial back pain complaints have been clearly and consistently identified. These limitations in knowledge have placed obvious constraints on the design of effective intervention programs. Recent information on the importance of perceptions of the nonphysical work environment and other psychosocial factors provide a broader perspective of the industrial back pain problems that may lead to more enlightened and effective approaches.

Scientific application of sports medicine principles for acute low back problems. The Agency for Health Care Policy and Research Low Back Guideline Panel (AHCPR, Guideline #14)

The Agency for Health Care Policy and Research Low Back Guideline Panel (AHCPR, Guideline #14) truly brought to life sports medicine principles in the care of the most common and expensive musculoskeletal problem by focusing on the basic activity paradigm of musculoskeletal limitations. Twenty-three experts and seven international consultants led a review of over 10,000 abstracts and evaluation of over 4,600 articles. This effort was to establish scientifically how any clinician can: 1) safely be sure that the patient only has a back problem, 2) offer safe options for comfort, and 3) concentrate on the real treatment for an activity intolerance with sports medicine principles: activity, not rest, begets activity tolerance. Evidence tables and their subsequent derivation as "Finding and Recommendation Statements" provide an understanding of what medical science can and cannot presently support as predictable.