The validation of visual analogue scales as ratio scale measures for chronic and experimental pain

Visual analogue scales (VAS) of sensory intensity and affective magnitude were validated as ratio scale measures for both chronic and experimental pain. Chronic pain patients and healthy volunteers made VAS sensory and affective responses to 6 noxious thermal stimuli (43, 45, 47, 48, 49 and 51 degrees C) applied for 5 sec to the forearm by a contact thermode. Sensory VAS and affective VAS responses to these temperatures yielded power functions with exponents 2.1 and 3.8, respectively; these functions were similar for pain patients and for volunteers. The power functions were predictive of estimated ratios of sensation or affect produced by pairs of standard temperatures (e.g. 47 and 49 degrees C), thereby providing direct evidence for ratio scaling properties of VAS. Vas sensory intensity responses to experimental pain, VAS sensory intensity responses to different levels of chronic pain, and direct temperature (experimental pain) matches to 3 levels of chronic pain were all internally consistent, thereby demonstrating the valid use of VAS for the measurement of and comparison between chronic pain and experimental heat pain.

Updated method guidelines for systematic reviews in the cochrane collaboration back review group

STUDY DESIGN

Descriptive method guidelines.

OBJECTIVES

To help reviewers design, conduct, and report reviews of trials in the field of back and neck pain.

SUMMARY OF BACKGROUND DATA

In 1997, the Cochrane Collaboration Back Review Group published method guidelines for systematic reviews. Since its publication, new methodologic evidence emerged and more experience was acquired in conducting reviews.

METHODS

All reviews and protocols of the Back Review Group were assessed for compliance with the 1997 method guidelines. Also, the most recent version of the Cochrane Handbook (4.1) was checked for new recommendations. In addition, some important topics that were not addressed in the 1997 method guidelines were included (e.g., methods for qualitative analysis, reporting of conclusions, and discussion of clinical relevance of the results). In May 2002, preliminary results were presented and discussed in a workshop. In two rounds, a list of all possible recommendations and the final draft were circulated for comments among the editors of the Back Review Group.

RESULTS

The recommendations are divided in five categories: literature search, inclusion criteria, methodologic quality assessment, data extraction, and data analysis. Each recommendation is classified in minimum criteria and further guidance. Additional recommendations are included regarding assessment of clinical relevance, and reporting of results and conclusions.

CONCLUSIONS

Systematic reviews need to be conducted as carefully as the trials they report and, to achieve full impact, systematic reviews need to meet high methodologic standards.

Expenditures and health status among adults with back and neck problems

CONTEXT

Back and neck problems are among the symptoms most commonly encountered in clinical practice. However, few studies have examined national trends in expenditures for back and neck problems or related these trends to health status measures.

OBJECTIVES

To estimate inpatient, outpatient, emergency department, and pharmacy expenditures related to back and neck problems in the United States from 1997 through 2005 and to examine associated trends in health status.

DESIGN AND SETTING

Age- and sex-adjusted analysis of the nationally representative Medical Expenditure Panel Survey (MEPS) from 1997 to 2005 using complex survey regression methods. The MEPS is a household survey of medical expenditures weighted to represent national estimates. Respondents were US adults (> 17 years) who self-reported back and neck problems (referred to as "spine problems" based on MEPS descriptions and International Classification of Diseases, Ninth Revision, Clinical Modification definitions).

MAIN OUTCOME MEASURES

Spine-related expenditures for health services (inflation-adjusted); annual surveys of self-reported health status.

RESULTS

National estimates were based on annual samples of survey respondents with and without self-reported spine problems from 1997 through 2005. A total of 23 045 respondents were sampled in 1997, including 3139 who reported spine problems. In 2005, the sample included 22 258 respondents, including 3187 who reported spine problems. In 1997, the mean age- and sex-adjusted medical costs for respondents with spine problems was $4695 (95% confidence interval [CI], $4181-$5209), compared with $2731 (95% CI, $2557-$2904) among those without spine problems (inflation-adjusted to 2005 dollars). In 2005, the mean age- and sex- adjusted medical expenditure among respondents with spine problems was $6096 (95% CI, $5670-$6522), compared with $3516 (95% CI, $3266-$3765) among those without spine problems. Total estimated expenditures among respondents with spine problems increased 65% (adjusted for inflation) from 1997 to 2005, more rapidly than overall health expenditures. The estimated proportion of persons with back or neck problems who self-reported physical functioning limitations increased from 20.7% (95% CI, 19.9%-21.4%) to 24.7% (95% CI, 23.7%-25.6%) from 1997 to 2005. Age- and sex-adjusted self-reported measures of mental health, physical functioning, work or school limitations, and social limitations among adults with spine problems were worse in 2005 than in 1997.

CONCLUSIONS

In this survey population, self-reported back and neck problems accounted for a large proportion of health care expenditures. These spine-related expenditures have increased substantially from 1997 to 2005, without evidence of corresponding improvement in self-assessed health status.

Reproducibility and responsiveness of health status measures. Statistics and strategies for evaluation

Before being introduced to wide use, health status instruments should be evaluated for reliability and validity. Increasingly, they are also tested for responsiveness to important clinical changes. Although standards exist for assessing these properties, confusion and inconsistency arise because multiple statistics are used for the same property; controversy exists over how to measure responsiveness; many statistics are unavailable on common software programs; strategies for measuring these properties vary; and it is often unclear how to define a clinically important change in patient status. Using data from a clinical trial of therapy for back pain, we demonstrate the calculation of several statistics for measuring reproducibility and responsiveness, and demonstrate relationships among them. Simple computational guides for several statistics are provided. We conclude that reproducibility should generally be quantified with the intraclass correlation coefficient rather than the more common Pearson r. Assessing reproducibility by retest at one-to-two week intervals (rather than a shorter interval) may result in more realistic estimates of the variability to be observed among control subjects in a longitudinal study. Instrument responsiveness should be quantified using indicators of effect size, a modified effect size statistic proposed by Guyatt, or the use of receiver operating characteristic (ROC) curves to describe how well various score changes can distinguish improved from unimproved patients.

The economic burden of back pain in the UK

This paper reports the results of a 'cost-of-illness' study of the socio-economic costs of back pain in the UK. It estimates the direct health care cost of back pain in 1998 to be pound1632 million. Approximately 35% of this cost relates to services provided in the private sector and thus is most likely paid for directly by patients and their families. With respect to the distribution of cost across different providers, 37% relates to care provided by physiotherapists and allied specialists, 31% is incurred in the hospital sector, 14% relates to primary care, 7% to medication, 6% to community care and 5% to radiology and imaging used for investigation purposes. However, the direct cost of back pain is insignificant compared to the cost of informal care and the production losses related to it, which total pound10668 million. Overall, back pain is one of the most costly conditions for which an economic analysis has been carried out in the UK and this is in line with findings in other countries. Further research is needed to establish the cost-effectiveness of alternative back pain treatments, so as to minimise cost and maximise the health benefit from the resources used in this area.

A randomized trial of vertebroplasty for osteoporotic spinal fractures

BACKGROUND

Vertebroplasty is commonly used to treat painful, osteoporotic vertebral compression fractures.

METHODS

In this multicenter trial, we randomly assigned 131 patients who had one to three painful osteoporotic vertebral compression fractures to undergo either vertebroplasty or a simulated procedure without cement (control group). The primary outcomes were scores on the modified Roland-Morris Disability Questionnaire (RDQ) (on a scale of 0 to 23, with higher scores indicating greater disability) and patients' ratings of average pain intensity during the preceding 24 hours at 1 month (on a scale of 0 to 10, with higher scores indicating more severe pain). Patients were allowed to cross over to the other study group after 1 month.

RESULTS

All patients underwent the assigned intervention (68 vertebroplasties and 63 simulated procedures). The baseline characteristics were similar in the two groups. At 1 month, there was no significant difference between the vertebroplasty group and the control group in either the RDQ score (difference, 0.7; 95% confidence interval [CI], -1.3 to 2.8; P=0.49) or the pain rating (difference, 0.7; 95% CI, -0.3 to 1.7; P=0.19). Both groups had immediate improvement in disability and pain scores after the intervention. Although the two groups did not differ significantly on any secondary outcome measure at 1 month, there was a trend toward a higher rate of clinically meaningful improvement in pain (a 30% decrease from baseline) in the vertebroplasty group (64% vs. 48%, P=0.06). At 3 months, there was a higher crossover rate in the control group than in the vertebroplasty group (51% vs. 13%, P<0.001) [corrected]. There was one serious adverse event in each group.

CONCLUSIONS

Improvements in pain and pain-related disability associated with osteoporotic compression fractures in patients treated with vertebroplasty were similar to the improvements in a control group. (ClinicalTrials.gov number, NCT00068822.)

A randomized trial of vertebroplasty for painful osteoporotic vertebral fractures

BACKGROUND

Vertebroplasty has become a common treatment for painful osteoporotic vertebral fractures, but there is limited evidence to support its use.

METHODS

We performed a multicenter, randomized, double-blind, placebo-controlled trial in which participants with one or two painful osteoporotic vertebral fractures that were of less than 12 months' duration and unhealed, as confirmed by magnetic resonance imaging, were randomly assigned to undergo vertebroplasty or a sham procedure. Participants were stratified according to treatment center, sex, and duration of symptoms (< 6 weeks or > or = 6 weeks). Outcomes were assessed at 1 week and at 1, 3, and 6 months. The primary outcome was overall pain (on a scale of 0 to 10, with 10 being the maximum imaginable pain) at 3 months.

RESULTS

A total of 78 participants were enrolled, and 71 (35 of 38 in the vertebroplasty group and 36 of 40 in the placebo group) completed the 6-month follow-up (91%). Vertebroplasty did not result in a significant advantage in any measured outcome at any time point. There were significant reductions in overall pain in both study groups at each follow-up assessment. At 3 months, the mean (+/-SD) reductions in the score for pain in the vertebroplasty and control groups were 2.6+/-2.9 and 1.9+/-3.3, respectively (adjusted between-group difference, 0.6; 95% confidence interval, -0.7 to 1.8). Similar improvements were seen in both groups with respect to pain at night and at rest, physical functioning, quality of life, and perceived improvement. Seven incident vertebral fractures (three in the vertebroplasty group and four in the placebo group) occurred during the 6-month follow-up period.

CONCLUSIONS

We found no beneficial effect of vertebroplasty as compared with a sham procedure in patients with painful osteoporotic vertebral fractures, at 1 week or at 1, 3, or 6 months after treatment. (Australian New Zealand Clinical Trials Registry number, ACTRN012605000079640.)

1987 Volvo award in clinical sciences. A new clinical model for the treatment of low-back pain

Because there is increasing concern about low-back disability and its current medical management, this analysis attempts to construct a new theoretic framework for treatment. Observations of natural history and epidemiology suggest that low-back pain should be a benign, self-limiting condition, that low back-disability as opposed to pain is a relatively recent Western epidemic, and that the role of medicine in that epidemic must be critically examined. The traditional medical model of disease is contrasted with a biopsychosocial model of illness to analyze success and failure in low-back disorders. Studies of the mathematical relationship between the elements of illness in chronic low-back pain suggest that the biopsychosocial concept can be used as an operational model that explains many clinical observations. This model is used to compare rest and active rehabilitation for low-back pain. Rest is the commonest treatment prescribed after analgesics but is based on a doubtful rationale, and there is little evidence of any lasting benefit. There is, however, little doubt about the harmful effects--especially of prolonged bed rest. Conversely, there is no evidence that activity is harmful and, contrary to common belief, it does not necessarily make the pain worse. Experimental studies clearly show that controlled exercises not only restore function, reduce distress and illness behavior, and promote return to work, but actually reduce pain. Clinical studies confirm the value of active rehabilitation in practice. To achieve the goal of treating patients rather than spines, we must approach low-back disability as an illness rather than low-back pain as a purely physical disease. We must distinguish pain as a purely the symptoms and signs of distress and illness behavior from those of physical disease, and nominal from substantive diagnoses. Management must change from a negative philosophy of rest for pain to more active restoration of function. Only a new model and understanding of illness by physicians and patients alike makes real change possible.

Estimates and patterns of direct health care expenditures among individuals with back pain in the United States

STUDY DESIGN

Secondary analysis of the 1998 Medical Expenditure Panel Survey.

OBJECTIVE

To estimate total health care expenditures incurred by individuals with back pain in the United States, calculate the incremental expenditures attributable to back pain among these individuals, and describe health care expenditure patterns of individuals with back pain.

SUMMARY OF BACKGROUND DATA

There is a lack of updated information on health care expenditures and expenditure patterns for individuals with back pain in the United States.

METHODS

This study used data from the 1998 Medical Expenditure Panel Survey, a national survey on health care utilization and expenditures. Total health care expenditures and per-capita expenditures among individuals with back pain were calculated. Multivariate regression models were used to estimate the incremental expenditures attributable to back pain. The expenditure patterns were examined by stratifying individuals with back pain by sociodemographic characteristics and medical diagnosis, and calculating per-capita expenditures for each stratum.

RESULTS

In 1998, total health care expenditures incurred by individuals with back pain in the United States reached 90.7 billion dollars and total incremental expenditures attributable to back pain among these persons were approximately 26.3 billion dollars. On average, individuals with back pain incurred health care expenditures about 60% higher than individuals without back pain (3,498 dollars vs. 2,178 dollars). Among back pain individuals, at least 75% of service expenditures were attributed to those with top 25% expenditure, and per-capita expenditures were generally higher for those who were older, female, white, medically insured, or suffered from disc disorders.

CONCLUSIONS

Health care expenditures for back pain in the United States in 1998 were substantial. The expenditures demonstrated wide variations among individuals with different clinical, demographic, and socioeconomic characteristics.

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.

Assessing the clinical significance of change scores recorded on subjective outcome measures

BACKGROUND

To date, clinical trials have relied almost exclusively on the statistical significance of changes in scores from outcome measures in interpreting the effectiveness of treatment interventions. It is becoming increasingly important, however, to determine the clinical rather than statistical significance of these change scores.

OBJECTIVE

To determine cutoff values for change scores that distinguish patients who have clinically improved from those who have not.

METHOD

Data were obtained from 165 back and 100 neck patients undergoing chiropractic treatment. Patients completed the Bournemouth Questionnaire (BQ) before treatment and the BQ and Patient's Global Impression of Change (PGIC) scale after treatment. Three statistical methods were applied to individual change scores on the BQ. These were (1) the Reliable Change Index (RCI); (2) the effect size (ES); and (3) the raw and percentage change scores. The PGIC scale was used as the "gold standard" of clinically significant change.

RESULTS

The RCI, using the cutoff value of >1.96, appropriately identified clinical improvement in back patients but not in neck patients. An individual ES of approximately 0.5 had the highest sensitivity and specificity in distinguishing back and neck patients who had undergone clinically significant improvement from those who had not. In terms of raw score changes, percentage BQ change scores [(raw change score/baseline score) x 100] of 47% and 34% were identified as having the highest sensitivity and specificity in distinguishing clinically significant improvement from nonimprovement in back and neck patients, respectively.

CONCLUSION

This study provides a methodological framework for identifying clinically significant change in patients. This approach has important implications in providing clinically relevant information about the effect of a treatment intervention in an individual patient.

Lumbar spinal stenosis: conservative or surgical management?: A prospective 10-year study

STUDY DESIGN

A cohort of 100 patients with symptomatic lumbar spinal stenosis, characterized in a previous article, were given surgical or conservative treatment and followed for 10 years.

OBJECTIVES

To identify the short- and long-term results after surgical and conservative treatment, and to determine whether clinical or radiologic predictors for the treatment result can be defined.

SUMMARY OF BACKGROUND DATA

Surgical decompression has been considered the rational treatment. However, clinical experience indicates that many patients do well with conservative treatment.

METHODS

In this study, 19 patients with severe symptoms were selected for surgical treatment and 50 patients with moderate symptoms for conservative treatment, whereas 31 patients were randomized between the conservative (n = 18) and surgical (n = 13) treatment groups. Pain was decisive for the choice of treatment group. All patients were observed for 10 years by clinical evaluation and questionnaires. The results, evaluated by patient and physician, were rated as excellent, fair, unchanged, or worse.

RESULTS

After a period of 3 months, relief of pain had occurred in most patients. Some had relief earlier, whereas for others it took 1 year. After a period of 4 years, excellent or fair results were found in half of the patients selected for conservative treatment, and in four fifths of the patients selected for surgery. Patients with an unsatisfactory result from conservative treatment were offered delayed surgery after 3 to 27 months (median, 3.5 months). The treatment result of delayed surgery was essentially similar to that of the initial group. The treatment result for the patients randomized for surgical treatment was considerably better than for the patients randomized for conservative treatment. Clinically significant deterioration of symptoms during the final 6 years of the follow-up period was not observed. Patients with multilevel afflictions, surgically treated or not, did not have a poorer outcome than those with single-level afflictions. Clinical or radiologic predictors for the final outcome were not found. There were no dropouts, except for 14 deaths.

CONCLUSIONS

The outcome was most favorable for surgical treatment. However, an initial conservative approach seems advisable for many patients because those with an unsatisfactory result can be treated surgically later with a good outcome.

The effect of graded activity on patients with subacute low back pain: a randomized prospective clinical study with an operant-conditioning behavioral approach

The aim of this study was to determine whether graded activity restored occupational function in industrial blue-collar workers who were sick-listed for 8 weeks because of subacute, nonspecific, mechanical low back pain (LBP). Patients with LBP, who had been examined by an orthopedic surgeon and a social worker, were randomly assigned to either an activity group (n = 51) or a control group (n = 52). Patients with defined orthopedic, medical, or psychiatric diagnoses were excluded before randomization. The graded activity program consisted of four parts: (1) measurements of functional capacity; (2) a work-place visit; (3) back school education; and (4) an individual, submaximal, gradually increased exercise program, with an operant-conditioning behavioral approach, based on the results of the tests and the demands of the patient's work. Records of the amount of sick leave taken over a 3-year period (ie, the 1-year periods before, during, and after intervention) were obtained from each patient's Social Insurance Office. The patients in the activity group returned to work significantly earlier than did the patients in the control group. The median number of physical therapist appointments before return to work was 5, and the average number of appointments was 10.7 (SD = 12.3). The average duration of sick leave attributable to LBP during the second follow-up year was 12.1 weeks (SD = 18.4) in the activity group and 19.6 weeks (SD = 20.7) in the control group. Four patients in the control group and 1 patient in the activity group received permanent disability pensions. The graded activity program made the patients occupationally functional again, as measured by return to work and significantly reduced long-term sick leave.

New criteria for inflammatory back pain in patients with chronic back pain: a real patient exercise by experts from the Assessment of SpondyloArthritis international Society (ASAS)

OBJECTIVE

Inflammatory back pain (IBP) is an important clinical symptom in patients with axial spondyloarthritis (SpA), and relevant for classification and diagnosis. In the present report, a new approach for the development of IBP classification criteria is discussed.

METHODS

Rheumatologists (n = 13) who are experts in SpA took part in a 2-day international workshop to investigate 20 patients with back pain and possible SpA. Each expert documented the presence/absence of clinical parameters typical for IBP, and judged whether IBP was considered present or absent based on the received information. This expert judgement was used as the dependent variable in a logistic regression analysis in order to identify those individual IBP parameters that contributed best to a diagnosis of IBP. The new set of IBP criteria was validated in a separate cohort of patients (n = 648).

RESULTS

Five parameters best explained IBP according to the experts. These were: (1) improvement with exercise (odds ratio (OR) 23.1); (2) pain at night (OR 20.4); (3) insidious onset (OR 12.7); (4) age at onset <40 years (OR 9.9); and (5) no improvement with rest (OR 7.7). If at least four out of these five parameters were fulfilled, the criteria had a sensitivity of 77.0% and specificity of 91.7% in the patients participating in the workshop, and 79.6% and 72.4%, respectively, in the validation cohort.

CONCLUSION

This new approach with real patients defines a set of IBP definition criteria using overall expert judgement on IBP as the gold standard. The IBP experts' criteria are robust, easy to apply and have good face validity.

Early identification of patients at risk of developing a persistent back problem: the predictive validity of the Orebro Musculoskeletal Pain Questionnaire

OBJECTIVE

To test the predictive utility of the Orebro Musculoskeletal Pain Screening Questionnaire in identifying patients at risk for developing persistent back pain problems.

DESIGN

Prospective, where participants completed the questionnaire and their cases were followed for 6 months to assess outcome with regard to pain, function, and absenteeism due to sickness.

PARTICIPANTS

One hundred seven patients, recruited from seven primary care units.

RESULTS

Discriminant analyses showed that the items on the questionnaire were significantly related to future problems. For absenteeism due to sickness, 68% of the patients were correctly classified into one of three groups, whereas an even distribution would have produced 33%. The analyses for function correctly classified 81%, and for pain 71%, into one of two groups, compared with a chance level of 50%. A total score analysis demonstrated that a cutoff score of 90 points had a sensitivity of 89% and a specificity of 65% for absenteeism due to sickness, and a sensitivity of 74% and a specificity of 79% for functional ability.

CONCLUSIONS

The results underscore that psychological variables are related to outcome 6 months later, and they replicate and extend earlier findings indicating that the Orebro Screening Questionnaire is a clinically reliable and valid instrument. The total score was a relatively good predictor of future absenteeism due to sickness as well as function, but not of pain. The results suggest that the instrument could be of value in isolating patients in need of early interventions and may promote the use of appropriate interventions for patients with psychological risk factors.

The North American spine society lumbar spine outcome assessment Instrument: reliability and validity tests

STUDY DESIGN

A cross-sectional study of a convenience sample of lumbar spine patients, with a subsample followed for retest reliability.

OBJECTIVES

To assess the instrument's reliability, validity, and acceptability to patients.

SUMMARY OF BACKGROUND DATA

Patients with eight diagnoses, four before surgery and four after surgery, were recruited from six orthopedic practices to test the questionnaire.

METHODS

One hundred sixty-seven patients were approached through the physician's office, yielding 136 usable questionnaires (84%) and 24-hour retests on 64 patients.

RESULTS

The questionnaire took about 20 minutes to administer and was acceptable to patients. The lumbar spine pain and disability and neurogenic symptoms subscales discriminated among patient groups as hypothesized and showed significantly better scores for patients independently judged successful by their physicians after surgery. Test-retest reliability and internal reliability were high (range, 0.85-0.97). Sample sizes of 20-37 would be needed to detect a 20% difference between two groups (alpha, 0.05; beta, 0.20).

CONCLUSIONS

The questionnaire should be considered for monitoring of individual patient's progress in treatment and for clinical trials.

A study of the natural history of low-back pain. Part II: development of guidelines for trials of treatment in primary care

In a prospective study of 230 episodes of low-back pain presenting in primary care, the natural history of the symptom of low-back pain has been described. Clinical features predictive of outcome have been identified in order to define groups of patients who were relatively homogeneous with respect to the outcome of the episode. A Disability Questionnaire performed more satisfactorily as an outcome measure than either absence from work or a simple pain-rating scale. Guidelines for future trials of treatment of back pain in primary care are described.

Spinal cord stimulation for patients with failed back surgery syndrome or complex regional pain syndrome: a systematic review of effectiveness and complications

We conducted a systematic review of the literature on the effectiveness of spinal cord stimulation (SCS) in relieving pain and improving functioning for patients with failed back surgery syndrome and complex regional pain syndrome (CRPS). We also reviewed SCS complications. Literature searches yielded 583 articles, of which seven met the inclusion criteria for the review of SCS effectiveness, and 15 others met the criteria only for the review of SCS complications. Two authors independently extracted data from each article, and then resolved discrepancies by discussion. We identified only one randomized trial, which found that physical therapy (PT) plus SCS, compared with PT alone, had a statistically significant but clinically modest effect at 6 and 12 months in relieving pain among patients with CRPS. Similarly, six other studies of much lower methodological quality suggest mild to moderate improvement in pain with SCS. Pain relief with SCS appears to decrease over time. The one randomized trial suggested no benefits of SCS in improving patient functioning. Although life-threatening complications with SCS are rare, other adverse events are frequent. On average, 34% of patients who received a stimulator had an adverse occurrence. We conclude with suggestions for methodologically stronger studies to provide more definitive data regarding the effectiveness of SCS in relieving pain and improving functioning, short- and long-term, among patients with chronic pain syndromes.

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.

Prolonged relief of pain by brief, intense transcutaneous somatic stimulation

The purpose of this study was to examine the effects of brief, intense transcutaneous electrical stimulations at trigger points or acupuncture points on severe clinical pain. The McGill Pain Questionnaire was used to measure the change in pain quality and intensity produced by stimulation. The data indicate that the procedure provides a powerful method for the control of some forms of severe pathological pain. The average pain decrease during stimulation sessions was 75% for pain due to peripheral nerve injury, 66% for phantom limb pain, 62% for shoulder-arm pain, and 60% for low-back pain. The duration of relief frequently outlasted the period of stimulation by several hours, occasionally for days or weeks. Different patterns of the amount and duration of pain relief were observed. Daily stimulation carried out at home by the patient sometimes provided gradually increasing relief over periods of weeks or months. Control experiments, which included two forms of placebo stimulation, showed that brief, intense electrical stimulation is significantly more effective than placebo contributions. Possible neural mechanisms that underlie these patterns of pain relief by brief, intense stimulation are discussed.

A controlled trial of transcutaneous electrical nerve stimulation (TENS) and exercise for chronic low back pain

A number of treatments are widely prescribed for chronic back pain, but few have been rigorously evaluated. We examined the effectiveness of transcutaneous electrical nerve stimulation (TENS), a program of stretching exercises, or a combination of both for low back pain. Patients with chronic low back pain (median duration, 4.1 years) were randomly assigned to receive daily treatment with TENS (n = 36), sham TENS (n = 36), TENS plus a program of exercises (n = 37), or sham TENS plus exercises (n = 36). After one month no clinically or statistically significant treatment effect of TENS was found on any of 11 indicators of outcome measuring pain, function, and back flexion; there was no interactive effect of TENS with exercise. Overall improvement in pain indicators was 47 percent with TENS and 42 percent with sham TENS (P not significant). The 95 percent confidence intervals for group differences excluded a major clinical benefit of TENS for most outcomes. By contrast, after one month patients in the exercise groups had significant improvement in self-rated pain scores, reduction in the frequency of pain, and greater levels of activity as compared with patients in the groups that did not exercise. The mean reported improvement in pain scores was 52 percent in the exercise groups and 37 percent in the nonexercise groups (P = 0.02). Two months after the active intervention, however, most patients had discontinued the exercises, and the initial improvements were gone. We conclude that for patients with chronic low back pain, treatment with TENS is no more effective than treatment with a placebo, and TENS adds no apparent benefit to that of exercise alone.

Low back pain of mechanical origin: randomised comparison of chiropractic and hospital outpatient treatment

OBJECTIVE

To compare chiropractic and hospital outpatient treatment for managing low back pain of mechanical origin.

DESIGN

Randomised controlled trial. Allocation to chiropractic or hospital management by minimisation to establish groups for analysis of results according to initial referral clinic, length of current episode, history, and severity of back pain. Patients were followed up for up two years.

SETTING

Chiropractic and hospital outpatient clinics in 11 centres.

PATIENTS

741 Patients aged 18-65 who had no contraindications to manipulation and who had not been treated within the past month.

INTERVENTIONS

Treatment at the discretion of the chiropractors, who used chiropractic manipulation in most patients, or of the hospital staff, who most commonly used Maitland mobilisation or manipulation, or both.

MAIN OUTCOME MEASURES

Changes in the score on the Oswestry pain disability questionnaire and in the results of tests of straight leg raising and lumbar flexion.

RESULTS

Chiropractic treatment was more effective than hospital outpatient management, mainly for patients with chronic or severe back pain. A benefit of about 7% points on the Oswestry scale was seen at two years. The benefit of chiropractic treatment became more evident throughout the follow up period. Secondary outcome measures also showed that chiropractic was more beneficial.

CONCLUSIONS

For patients with low back pain in whom manipulation is not contraindicated chiropractic almost certainly confers worthwhile, long term benefit in comparison with hospital outpatient management. The benefit is seen mainly in those with chronic or severe pain. Introducing chiropractic into NHS practice should be considered.

Back pain in primary care. Outcomes at 1 year

Outcomes of primary care back pain patients (N = 1128) were studied at 1 year after seeking care. Changes in depression depending on outcome, and predictors of poor outcome were evaluated. Less than one back pain patient in five reported recent onset (first onset within the previous 6 months). One year after seeking care, the large majority of both recent and nonrecent-onset patients reported having back pain in the previous month (69% vs. 82%). A significant minority of both recent and nonrecent-onset patients had either a poor functional outcome (14% vs. 21%) or continuing high intensity pain without appreciable disability (10% vs. 16%). Predictors of poor outcome included pain-related disability, days in pain, lower educational attainment, and female gender. Among initially dysfunctional patients with persistent pain, one half were improved and one third had a good outcome at the 1-year follow-up. Among initially dysfunctional patients who experienced a good outcome, elevated depressive symptoms improved to normal levels at follow-up. The outcome of back pain was predicted by pain-related disability and days in pain rather than by recency of onset, so it may be more meaningful to distinguish characteristic levels of pain intensity, pain-related disability, and pain persistence than to classify patients as acute or chronic.