Development of a screening instrument for risk factors of persistent pain after breast cancer surgery.

BACKGROUND: Persistent postsurgical pain can have a significant effect on the quality of life of women being treated for breast cancer. The aim of this prospective study was to develop a screening tool to identify presurgical demographic, psychological and treatment-related factors that predict persistence of significant pain in the operated area after 6 months from surgery. METHODS: Background and self-reported questionnaire data were collected the day before surgery and combined with treatment-related data. Pain in the operated area was assessed 6 months after surgery with a questionnaire. The Bayesian model was used for the development of a screening tool. RESULTS: Report of preoperative chronic pain, more than four or more previous operations, preoperative pain in the area to be operated, high body mass index, previous smoking and older age were included in the six-factor model that best predicted significant pain at the follow-up in the 489 women studied. CONCLUSION: A six-factor risk index was developed to estimate the risk of developing significant pain after breast cancer surgery. Neither treatment- nor mood-related variables were included in the model. Identification of risk factors may lead to prevention of persistent postsurgery pain. This tool could be used for target prevention to those who are at the highest risk of developing persistent postsurgery pain.

The relationship of disability (Oswestry) and pain drawings to functional testing.

UNLABELLED: There was much enthusiasm about the development of computerized dynamometry in providing large quantities of data to objectively assess muscle performance. However, a much more basic issue arose questioning what these machines actual measure, particularly in pain populations. The purpose of the present study was to determine whether patients' self-reported disability and pain expression, as evaluated with simple questionnaires, were related to isokinetic performance in low back pain patients. METHOD: Oswestry Disability Questionnaires and pain drawings were collected from 76 patients undergoing isokinetic testing upon entering a physical rehabilitation program. Isokinetic trunk testing was performed in the standing position and results recorded for flexion and extension at speeds of 50 degrees, 100 degrees, and 150 degrees per second. RESULTS: Patients indicating minimal disability on the Oswestry questionnaire performed better than those indicating greater levels of disability (P < 0.05; ANOVA with Tukey adjustment for multiple comparisons). Patients with greater pain drawing scores, indicating unusual pain patterns, performed more poorly during isokinetic testing than those with normal drawings (P < 0.05). Regression analysis revealed that the lifting question from the Oswestry questionnaire, pain drawings scores, and sex were all significantly related to isokinetic performance and could account for 37.6-48.1% of the variance in performance (varying with speed of test). CONCLUSIONS: The results of this study indicate that isokinetic test values are significantly influenced by a patient's self-reported disability and pain expression, which can be evaluated using simple tools such as pain drawings and the Oswestry questionnaire. This study supports the supposition that dynamometry testing is related to factors other than muscle performance.

Do psychological factors predict changes in musculoskeletal pain? A prospective, two-year follow-up study of a working population.

Our aim was to determine the predictive value of some psychometric instruments for the development and persistence of musculoskeletal pain. In 452 subjects, pain in the shoulder, neck, and low back during the preceding year was assessed at baseline, one year, and two years' follow-up. Psychological distress, depression, self-efficacy beliefs, subjective work prognosis, disability, and work characteristics were assessed at baseline. The best predictor of future pain was disability. The psychometric measures did not predict changes in pain. The explanatory power of the variables in the multivariate analyses was low. Perceived disability in persons with musculoskeletal symptoms should be acknowledged early. The traditional research paradigm focusing on a few hypothetically relevant variables does not take into account the reflective, dynamic, reciprocal nature of human behavior during the process of recovery from or development of a pain problem.

Assessment of depression in chronic musculoskeletal pain patients.

OBJECTIVE: To analyze how the cognitive, affective, and somatic-vegetative symptoms of depression included in the modified Zung Self-Rating Depression Scale (ZSDS) relate to pain severity. SUBJECTS: Three groups of subjects were compared. The "no pain" group (n = 64) reported no musculoskeletal symptoms during the preceding year, the "low pain" group (n = 119) had a pain rating of < or = 4, and the "high pain" group (n = 137) had a rating of > or = 5 on a numerical pain rating scale (0-10). METHODS: Sum scores of the ZSDS and means of separate items in the three subgroups were compared. Factor analyses were performed to evaluate the structure of the ZSDS, and differences between subgroups on weighted factor scores were analyzed. RESULTS: The "high pain" group differed statistically significantly from both other groups on the sum score and on most of the items. Comparison of weighted factor scores in a three-factor solution revealed that in Factor I, "Psychic Energy," the "high pain" group differed from both other groups. In Factor II, "Despair," no differences between groups were found, while in Factor III, "Sleep problems," statistically significant differences were found between all subgroups; more severe pain was associated with more sleep problems, fatigue, and restlessness. CONCLUSION: ZSDS items describing symptoms which could be a consequence of the pain problem (e.g., sleep problems) are clearly related more to pain severity than other indicators of depression--e.g., feelings of hopelessness. A diagnosis of depression based on a sum score of an inventory which contains somatic-vegetative signs of depression may lead to an overestimation of depression in chronic musculoskeletal pain patients. in chronic musculoskeletal pain patients.

Isokinetic performance in low back pain patients: The predictive power of the Self-Efficacy Scale.

The Self-Efficacy Scale (SES) has been found to predict isokinetic performance better than anthropometric variables. This study tests the predictive power of SES further against other measures of efficacy expectancies as well as measures of depression and perceived disability. A group of 105 chronic back pain patients was administered Beck's Depression Inventory (BDI), SES, the Pain Self-Efficacy Questionnaire (PSEQ), and the Oswestry low back pain disability questionnaire (OSWESTRY). Total isokinetic work done was measured at slow, medium and high speeds, for which multiple regression models were fitted controlling for sex, age, weight and height. The results confirmed SES to be the best overall predictor of isokinetic performance. BDI was not significant as a predictor of isokinetic performance. The models also revealed that SES predicts less well with increases in the test speed, particularly in extension. These results provide further evidence of the diagnostic value of SES relative to OSWESTRY and PSEQ.

Anthropometric variables, self-efficacy beliefs, and pain and disability ratings on the isokinetic performance of low back pain patients.

OBJECTIVES: This study investigated how age, sex, height, body weight, self-efficacy beliefs, pain, and subjective disability predict the performance of low back pain patients on an isokinetic trunk muscle test. METHODS: One hundred and five patients participated in the study. Dependent variables were isokinetic flexion and extension strength measured as total work done at speeds 50, 100, and 150 degrees/second. RESULTS: The anthropometric measures were poor predictors, height being the only significant one. Body weight and age were of no relevance for the performance. Subjective pain and disability had negative effects on the performance of men, but not of women. Self-efficacy beliefs, i.e., the patient's belief in his or her capability to endure physical activities, was the most powerful predictor. CONCLUSION: For the purpose of validation, standardization, and interpretation of isokinetic performance in low back pain patients, these factors should be taken into account.

Outcome of two multimodal back treatment programs with and without intensive physical training.

We compared the results of two multimodal back treatment programs (program A: n = 134; program B: n = 175) using pain, functional capacity, sickness absence, subjective state of health, depression, and work status as outcome variables. Whereas in program A exercise was guided by pain, in program B a "no pain, no gain" rationale was used as a basis for intensive physical training. Neither of the programs included direct attempts to influence the patient's environment (i.e., to find employment or to modify working conditions). In both programs, a clear decrease in pain and an increase in functional capacity was found from the pretreatment phase to the 12-month follow-up. These changes were, however, stronger in program B. Days of absence decreased significantly in group B, but the change was not significantly different from that in group A. On the whole, the more intensive training showed somewhat better results, even though the difference was not substantial. In contrast to some earlier results, there was no statistically significant increase in the proportion of those employed after treatment in either group. The results indicate that intensive physical exercise does not, as such, solve the problem of back disability in a country that has a highly developed social security system. More active interventions in work and work-life are needed.

Effects and follow-up of a multimodal treatment program including intensive physical training for low back pain patients.

The results of a comprehensive 4-week treatment program including intensive physical training were evaluated in 65 chronic low back pain patients. Marked increases in measures of spinal mobility, trunk muscle strength and lifting capacity were found during the treatment, but no average increase in pain ratings. At 3-week and 12-month follow-ups a statistically significant decrease in subjective disability and pain was found, but the percentage of patients who were working was unchanged. This points to a need for more work-oriented rehabilitation efforts in the treatment.

Determinants of pain behaviour in patients with chronic low back pain.

Experience of pain is manifested by a subject's behaviour, i.e. by verbalization, movements, facial expressions etc. Experience of pain is a latent construct, and the question of whether the pain is "real" becomes secondary when the behavioural aspect is emphasised: "When the patient communicates pain, then there is a pain problem". The task of the clinician and the researcher is to find out what is behind a person's response to pain. The pain behaviour is determined by many factors. These include psychological suffering due to emotional distress; learning processes regulating pain behaviour; anticipated pain and fear of pain as a cause of passivity and avoidance behaviour in chronic low back pain patients; the influence of cognitive factors, particularly the relationship between negative expectations, cognitive distortion and activity; and finally, the role of psychological distress in chronic pain. These factors are discussed in this paper. Some empirical studies are briefly reviewed to illustrate the topic. Implication of these conceptualizations for treatment of and outcome research in chronic low back pain will be briefly discussed.