Influence of an outpatient multidisciplinary pain management program on the health-related quality of life and the physical fitness of chronic pain patients
© Joos et al; licensee BioMed Central Ltd. 2004
Received: 20 January 2003
Accepted: 17 March 2004
Published: 17 March 2004
Approximately 10 to 20 percent of the population is suffering from chronic pain. Since this represents a major contribution to the costs of the health care system, more efficient measures and interventions to treat these patients are sought.
The development of general health and physical activity of patients with chronic pain was assessed in an interdisciplinary outpatient pain management program (IOPP). 36 patients with an average age of 48 years were included in the IOPP. Subjective assessment of well-being was performed at five time points (baseline, post intervention and 3, 6, and 12 months thereafter) by using standardized questionnaires. The study focused on the quality of life survey Medical Outcomes Study Short Form-36, which is a validated instrument with established reliability and sensitivity. In addition, the patients participated in physical assessment testing strength, power, endurance, and mobility.
Prior to therapy a substantial impairment was found on different levels. Marked improvements in the psychological parameters were obtained by the end of the program. No success was achieved with regard to the physical assessments.
Although many different studies have evaluated similar programs, only few of them have attained positive results such as improvements of general quality of life or of physical strength. Often no difference from the control group could be detected only some months after the intervention. In the present study no significant persistent improvement of well-being occurred. Possible reasons are either wrong instruments, wrong selection of patients or wrong interventions.
KeywordsLow back pain depression chronification pain intervention program quality of life
Instruments for the assessment of general health (selection)
Quality of Well-Being (QWB)
Mobility, physical and social activity
Sickness Impact Factor (SIP)
Movement, body care, mobility, emotional behavior, awareness, communication, work, sleep, household, leisure time
Beck Depression Inventory (BDI)
Affective distress and severity of depression in 21 items (range 0–63)
Hospital Anxiety and Depression Scale (HADS)
Survey on anxiety and depression
Psychological General Well-Being Scale (PGWB)
22 items on anxiety, depression, vitality, positive well-being, self-discipline, general health (range 0–110)
Visual Analogue Scale (VAS)
Pain intensity: Likert scale from 0 (no pain) to 5 (untenable pain)
Nottingham Health Profile (NHP)
Physical function, pain, emotional reactions, power, sleep, social isolation
Pain Self-Efficacy Questionnaire (PSEQ)
Various activities still feasible in spite of pain (e.g. household)
Pain Anxiety Symptoms Scale (PASS)
40 items on fear and anxiety responses specific to pain
Short Form 12 (SF-12)
Physical and psychological health
MOS Short Form 36 (SF-36)
Physical, psychological and social function, role behavior caused by physical and psychogenic disorder, general health, pain and vitality
Number of patients
48 ± 2.0
Duration of pain ± SEM (months)
74 ± 17.4
Degenerative and other non-inflammatory spinal column diseases:
Cervical disease: cervicovertebral syndrome
cervical compression syndrome
Thoracic disease: thoracovertebral syndrome
thoracic compression syndrome
Lumbar disease: lumbovertebral syndrome
lumbar spondylogenic syndrome
radicular compression syndrome
State following disc surgery / discopathy
Soft tissue rheumatism
Systemic inflammatory joint and spinal column diseases
Other origins: constitutional weakness of connective tissue (ligament insufficiency)
Somatisation disorder, impairment of coping with pain
Psychogenic problems (depression, phobia, migraine, etc.)
Psychogenic stress disorders
Various reasons for premature discontinuation of IOPP:
• Incompatible ideas on concept of pain program
• Work overload
• Severe pain
• Physician prescribed exclusion (e.g. following acquired disc hernia)
Development of GH Short Form-36 (SF-36) during the IOPP
Comparison of pre/post pain intervention
The patients presented with marked deficiencies in the eight categories of the SF-36 before, as well as after completion of the IOPP. They were particularly impaired with regard to the parameters role-physical [RP] and bodily pain (BP). An alteration of the score values by 6 to 8 points (per dimension) was considered as clinically significant .
Mean ± SEM of the eight health categories of SF-36
39.8 ± 3.6
39.8 ± 3.7
43.5 ± 4.8
44.1 ± 4.8
24.0 ± 9.9
10.5 ± 3.8
12.9 ± 3.8
13.2 ± 2.6
13.6 ± 3.4
10.0 ± 6.1
19.1 ± 2.0
22.0 ± 2.6
23.3 ± 3.7
27.9 ± 2.2
17.4 ± 4.0
42.5 ± 2.7
42.2 ± 2.5
36.1 ± 1.9
44.6 ± 3.6
38.4 ± 2.9
28.9 ± 2.5
31.8 ± 2.7
34.1 ± 3.2
37.1 ± 3.5
37.0 ± 8.5
40.3 ± 4.2
42.2 ± 4.1
46.3 ± 5.6
45.5 ± 6.6
32.5 ± 10.2
35.5 ± 7.3
48.3 ± 7.1
49.0 ± 8.9
66.7 ± 8.9*
41.7 ± 18.8
46.8 ± 3.6
53.8 ± 3.2
55.3 ± 4.1
56.7 ± 4.1
48.0 ± 10.7
Chronic pain causes predominantly physical impairment; subsequently and often as a consequence psychological problems follow.
Comparisons after the IOPP (post) with follow-up 1,2 and 3 (3, 6, and 12 months, respectively, following ambulatory intervention)
Physical functioning (PF) improved after six months by an average of 4 points (clinically non-significant). After the third and the last follow-up a marked and clinically significant deterioration far below the starting values was observed. RP remained constantly low over time.
Development of psychological factors and pain
6 months after the program BP clearly decreased. However, this success could not be maintained. After the following 6 months (i.e. 15 months after beginning of the study) pain increased again and on average even exceeded the original intensity. The same was observed for ME and RE; after 6 months a significant improvement was found for both parameters, which was also reduced after one year in such a way that no difference from pre-treatment remained. However, the number of patients remaining in the study until follow-up (fup) 3 was too low to be statistically calculated.
GH comparison between women and men
Development of physical fitness (assessment tests) during the IOPP
Based on the sociodemographic survey, more than 4/5 (86%) of all patients were active or moderately active before the current pain episode. At the start of the intervention all had a diminished degree of physical activity, 76% were entirely inactive. More than half of the patients were no longer able to carry out sports.
Strength of upper arm and femoral muscles pre and post IOPP
Elbow flexion left
11.4 ± 1.8
11.5 ± 1.4
Elbow flexion right
12.2 ± 1.8
11.0 ± 1.8
Elbow extension left
8.6 ± 1.1
9.2 ± 0.9
Elbow extension right
9.7 ± 1.5
8.4 ± 1.4
Knee flexion left
12.4 ± 2.5
8.2 ± 1.4
Knee flexion right
12.4 ± 1.9
10.2 ± 1.5
Knee extension left
16.7 ± 3.2
13.0 ± 2.2
Knee extension right
19.8 ± 3.1
17.7 ± 2.3
The interdisciplinary cooperation of physicians, psychologists, and physical therapists is exceptionally helpful in the treatment of patients suffering from complex health problems . Many studies have examined interdisciplinary programs, some of them found a positive outcome [3, 24]. A meta-analysis performed by Flor et al.  found that 75% of the patients recovered from the pain disorders. In the studies of Garrat et al. (1993) and Lyons et al. (1994) the SF-36 scores were less suppressed in patients who had an interdisciplinary treatment than in those who never underwent a pain intervention program [25, 26].
In general, the comparability of different pain programs is limited due to differences in treatment, patient groups, evaluation of the results, and follow-up periods . In the above-mentioned analysis of the SF-36 only a minor, non-significant improvement of the psychological healthiness and vitality was observed. In contrast, various other studies achieved comparatively slightly better results . Peters et al. found a loss of treatment effect after 12 months .
In the IOPP deterioration already occurred after 6 months. In 1996, a study by Williams et al.  observed better results even though the duration of their therapy program was only 9 weeks. This raises the question whether the duration of the IOPP could be decreased. Costs are an important factor of pain intervention programs; long-term follow-up studies are therefore rare . Deardorff et al. showed a significant improvement of the physical parameters in a group of ambulatory and interdisciplinary treated patients . Flavell et al. studied a pain program with duration of only 6 weeks. However, after a significant initial increase the walking distance remained unchanged or even returned to baseline values during the follow-up . In contrast to these studies, physical strength and fitness of our patients remained stable during the IOPP. The results of the physical components of the SF-36 appeared to correlate with those of the assessment tests. McCracken et al. showed recently that the levels of physical activity could be increased by an interdisciplinary treatment without a simultaneous decline of pain .
A major problem encountered with the IOPP was a relatively high rate of premature termination. It has been shown that individualized trainings, such as those employed in the IOPP, can diminish the duration of pain episodes . Various studies have assessed the intensity of pain. Jensen et al. 1999  has already confirmed that pain surveys, such as those used in our evaluation, are more suitable than questionnaires restricted to only a single time point.
A high prevalence of depression was seen in the present analysis, and in previous studies a correlation of self estimated pain with psychological symptoms such as anxiety and depression has been found . Overall, a high number of disturbances in coping with pain (32%) and/or psychological problems (26%) were observed in the present study. Previous studies also found significant correlation between the duration of pain and the occurrence of major depression . In the estimation of psychological well-being, the subscales of SF-36 turned out to be complementary to the hospital anxiety and depression scale (HADS) and to the psychological general well-being scale (PGWB) .
Vasseljen et al. postulated that disadvantageous working conditions might be responsible for chronic pain of shoulder and neck . One third of the subjects participating in the IOPP attended only elementary schools and 50% were carrying out (or carried out in their last job) a moderately demanding physical occupation. The high number of patients who have not passed an apprenticeship indicates that disadvantages in employment (often combined with a physically wearing workload) can cause pain encompassing the vertebral column. Nonetheless, individuals with an academic degree were also affected. Chronic pain is not caused by physically demanding work alone; it also occurred in 26% of those who had a mostly sitting activity during their current (or last) occupation.
The success of rehabilitation was inferior in women than in men in the study of Jensen et al. . They concluded, that distinct treatment strategies for men and women should be developed. In the IOPP, the GH of women remained stable even one year post-discharge, while that of men decreased significantly. However, the reason for this unexpected finding remains unclear.
Thirty different treatment centers in the US, Canada, Europe, and New Zealand were evaluated in 1992 by Linssen et al. . The authors concluded that most of the offered treatment programs were highly complex and expensive, were adjusted to closely selected patient groups, and exhibited high dropout rates. It appears that these shortcomings could not be eliminated in the past years.
The disappointing success of the IOPP raises the following questions: are more specific criteria required for the treatment of diverse patients? Should the inclusion criteria be narrowed? Has the number of patients to be increased? Are the methods used sufficiently sensitive? Are the patients treated at the appropriate time point?
The statistical power of a trial depends on a sufficiently high number of participants. Part of the question could possibly be better resolved by a multicentric proceeding .
Among the high number of existing instruments it is difficult to select the most suitable. The SF-36 is a valid method for the assessment of general health .
Timing of treatment
Patients who underwent an interdisciplinary treatment without delay revealed less pain and a better psychological condition . Early onset of therapy is thought to inhibit a possible chronification . A shorter previous history of pain, a high extent of occupation before the program, preconditions related to profession and education, as well as a general elevated level of activity turned out to be positive predictors of treatment success .
The participants of our study stated that they have profited by the IOPP with an average goal attainment of 72.3%, which indicates that a progress towards higher quality of life and greater self-determination was achieved. However, these experiences also confirmed that the participating patients are suffering from a complex disease, which is combined to some extent with violent psychosocial impairments. Due to psychosomatic components, as well as partially major disorders of perception and thinking, an interdisciplinary proceeding with the rehabilitation program is required. A substantial need for pain management programs exists; hence it is useful to optimize them and to evaluate the long-term effectiveness. Based on the presented findings, the content and structure of the IOPP was largely modified in April 2001. First preliminary results are encouraging . Further data on the outcome will be presented as soon as this ongoing study is completed.
One third of the 36 patients who completed the IOPP attended elementary school, one third had visited a vocational, trade, or business school, or an apprenticeship, and the remaining third had higher education. None of the patients carried out a very demanding physical occupation recently. Only one patient (3%) was capable to full-time work. Seven men and 14 women could earn their living with their income. One third had economical problems. Almost 30% did not obtain assistance from their family, although 70% lived together with his or her wife/husband. Three quarters lived in an urban setting. In one third the average history of suffering from chronic pain exceeded six years. 38% of the patients indicated that pain was the predominate nuisance, followed by inability to work (24%), restrictions related to free time, occupation, housekeeping, friends and quality of life (16%), psychological difficulties due to pain (11%) and loss of independence (4%). 62% were non-smoking and none said that they consume alcohol several times per day. 35% drunk no alcohol at all.
Design of the pain program
The IOPP consisted of a theoretical section, painting therapy, medical training therapy (MTT), group psychotherapy, relaxation therapy, medical motion therapy, and physiotherapeutic, psychotherapeutic and/or medicinal individual therapies adapted to individual patient problematic, and one evening with family members.
Various questionnaires were completed before (pre) and at the end of the program (post), as well as 3 (fup1), 6 (fup2) and 12 months (fup3) after completion of the program. This comprised of the SF-36 , health-related questionnaire (HADS-D, ), the multidimensional pain questionnaire (MPI-D, ), questions on coping with pain (CSQ, ), a sociodemographic and socioeconomic survey, (the model sheet ), the examination of goal achievement (GAS, ) and a pain and sleep diary. In addition the participants underwent body assessment tests to determine their development in the physical field.
Assessment of subjective well-being
The health-related (subjective) quality of life assessment was performed by the Medical Outcome Study SF-36 . A German translation of the international standard version was used . Questions refer to the past 4 weeks (standard version). The SF-36 consists of 36 items with 8 subscales and two summary scores for a physical (PCS=physical component summary) and a psychological component (MCS=mental component summary), respectively. Calculations of the scores were done according to Ware et al. . Scales were transformed into values ranging from 0 to 100. Higher values always indicate a better health condition.
Physical strength was evaluated by various assessment tests. In the step-test patients stepped up and down on a chest as often as possible. The arm holding test determined the time during which an on the back lying patient was able to hold two weights with stretched arms. In addition, the patients indicated their momentary pain intensity on a numerical scale. The Waddell test was used to discern physical from non-organic symptoms in back pain patients . Coordination and equilibrium were examined by single leg standing and by a walk on balance boards. During flexibility assessment the patients had to reach forward to the toes with extended knees in a seated position (sit and reach test). Patients were also asked to lift a box loaded with 2.5 kg from floor to waist or from waist to head level, repeated five times. The weight was then progressively increased by 2.5 kg (container test). Endurance was assessed at sub-maximal workload in an ergometer test starting with a power of 25 Watt during 4 minutes. Then the patients were ask for their perceived exertion according to the Borg scale before the applied power was gradually increased by 25 Watt. Finally the maximal isometric flexion and extension strength of the left and right upper arm and thigh muscles (elbow extension and flexion, knee extension and flexion) were evaluated .
Statistical analysis was done using SPSS (Version 7.0, SPSS Inc., Chicago, USA). Significant differences are based on non-parametric tests. Differences of matched samples were established by using the Wilcoxon test. P-values < 0.05 were considered as statistically significant.
List of abbreviations used
interdisciplinary outpatient pain management program fup1, fup2, fup3: follow-up 1, 2, and 3
We thank L. Ryser for excellent patient care, D. Bühler for assistance with physiotherapy, Dr. W. Steiner for IT support and L. Pobjoy for manuscript preparation.
- Becker N, Bondegaard Thomsen A, Olsen AK, Sjogren P, Bech P, Eriksen J: Pain epidemiology and health related quality of life in chronic non-malignant pain patients referred to a Danish multidimensionary pain center. Pain. 1997, 73: 393-400. 10.1016/S0304-3959(97)00126-7.View ArticlePubMedGoogle Scholar
- Geissner E, Flor H: Klinisch-psychologische Schmerzforschung. Z Klin Psychol. 1999, 28: 233-234. 10.1026//0084-53184.108.40.206.View ArticleGoogle Scholar
- Flor H, Fydrich T, Turk D: Efficacy of multidisciplinary pain treatment centers: a meta-analytic review. Pain. 1992, 49: 221-230. 10.1016/0304-3959(92)90145-2.View ArticlePubMedGoogle Scholar
- Malone MD, Strube MJ, Scogin FR: Meta-analysis of non-medical treatments for chronic pain. Pain. 1988, 34: 231-244. 10.1016/0304-3959(88)90118-2.View ArticlePubMedGoogle Scholar
- Magni G, Moreschi C, Rigatti-Luchini S, Merskey H: Prospective study on the relationship between depressive symptome and chronic muskuloskeletal pain. Pain. 1994, 56: 289-297. 10.1016/0304-3959(94)90167-8.View ArticlePubMedGoogle Scholar
- Holmstrom E, Moritz U: Low back pain –– correspondence between questionnaire, interview and clinical examination. Scand J Rehabil Med. 1991, 23: 119-125.PubMedGoogle Scholar
- Sangha O, Stucki G: Patienten-zentrierte Evaluation der Krankheitsauswirkungen bei muskuloskelettalen Erkrankungen: Uebersicht über die wichtigsten Outcome-Instrumente. Z Rheumatol. 1997, 56: 322-333. 10.1007/s003930050046.View ArticlePubMedGoogle Scholar
- Balaban DJ, Sagi PC, Goldfarb NI, Nettler S: Weigths for scoring the quality of well-being instrument among rheumatoid arthritics. A comparison to general population weights. Med Care. 1986, 24: 973-980.View ArticlePubMedGoogle Scholar
- Kessler S, Jäckel WH, Cziske R, Potthoff P, Jacobi E: Sickness Impact Measurement Scales: Validierung einer deutschen Version. Z Rheumatol. 1990, 49: 48-Google Scholar
- Beck AT, Steer RA, Garbin MG: Psychometric properties of the Beck Depression Inventory: twenty-five years of evaluation. Clin Psychol Rev. 1988, 8: 77-100. 10.1016/0272-7358(88)90050-5.View ArticleGoogle Scholar
- Zigmond AS, Snaith RP: The hospital anxiety and depression scale. Acta Psychiatr Scand. 1983, 67: 361-370.View ArticlePubMedGoogle Scholar
- Dupuy HJ: The psychological general well-being (PGWB) index. In: Assessment of quality of life in clinical trials of cardiovascular therapies. Edited by: Wenger NK, Mattson ME, Furberg JF, Elinson JA. 1984, New York, LeJacq, 170-183.Google Scholar
- Dworkin SF, von Korff M, Witney CW, LeResche L, Dicker BG, Barlow W: Measurement of characteristic pain intensity in field research. Pain. 1990, Suppl 5: 290-10.1016/0304-3959(90)92696-N.View ArticleGoogle Scholar
- McDowell IM, Martini CJ, Waugh W: A method for self-assessment of disability before and after hip replacement operations. Br Med J. 1978, 2: 857-859.View ArticlePubMedPubMed CentralGoogle Scholar
- Nicholas MK: An evaluation of cognitive, behavioural and relaxation treatments for chronic low back pain. PhD thesis, University of Sydney, Australia. 1988Google Scholar
- McCracken LM, Gross RT: The Pain Anxiety Symptoms Scale (PASS) and the assessment of emotional responses to pain. In: Innovation in clinical practice: a sourcebook. Edited by: VandeCreek L, Knapp S, Jackson TL. 1995, Sarasota, Professional Resources Press, 14: 309-321.Google Scholar
- Ware JE, Kosinski M, Keller SD: A 12-Item Short-Form Health Survey: construction of scales and preliminary tests of reliability and validity. Med Care. 1996, 34: 220-233. 10.1097/00005650-199603000-00003.View ArticlePubMedGoogle Scholar
- Ware JE, Sherbourne CD: The MOS 36-item short-form health survey (SF-36). I. Conceptual framework and item selection. Med Care. 1992, 30: 473-483.View ArticlePubMedGoogle Scholar
- Schipper H: Guidelines and caveats for quality of life measurement in clinical practice and research. Oncology Huntingt. 1990, 4: 51-57.PubMedGoogle Scholar
- Rosomoff HL, Fishbain DA, Goldberg M, Santana R, Rosomoff RS: Physical findings in patients with chronic intractable benign pain of the neck and/or back. Pain. 1989, 37: 279-287. 10.1016/0304-3959(89)90192-9.View ArticlePubMedGoogle Scholar
- Bronfort G, Bouter LM: Responsivness of general health status in chronic low back pain: a comparison of the COOP Charts and the SF-36. Pain. 1999, 83: 201-209. 10.1016/S0304-3959(99)00103-7.View ArticlePubMedGoogle Scholar
- Ware JE, Snow KK, Kosinski M, Gandek B: SF-36 Health survey manual and interpretation guide. Boston, MA: New England Medical Centre, The Health Institute. Orion Software Development, Santa Clara, USA. 1993Google Scholar
- Fordyce WE: Psychological factors in the failed back. Int Disabil Stud. 1988, 10: 29-31.View ArticlePubMedGoogle Scholar
- Morley S, Eccleston C, Williams A: Systematic review and meta-analysis of randomized controlled trials of cognitive behaviour therapy and behaviour therapy for chronic pain in adults, excluding headaches. Pain. 1999, 80: 1-13. 10.1016/S0304-3959(98)00255-3.View ArticlePubMedGoogle Scholar
- Garratt AM, Ruta DA, Abdalla MI, Buckingham JK, Russell IT: The SF-36 health survey questionnaire: an outcome measure suitable for routine use within the NHS?. BMJ. 1993, 306: 1440-1444.View ArticlePubMedPubMed CentralGoogle Scholar
- Lyons RA, Lo SV, Littlepage BN: Comparative health status of patients with 11 common illnesses in Wales. J Epidemiol Community Health. 1994, 48: 388-390.View ArticlePubMedPubMed CentralGoogle Scholar
- Harkapaa K, Mellin G, Jarvikoski A, Hurri H: A controlled study on the outcome of inpatient and outpatient treatment of low back pain. Part III. Long-term follow-up of pain, disability, and compliance. Scand J Rehabil Med. 1990, 22: 181-188.PubMedGoogle Scholar
- Becker N, Sjogren P, Bech P, Olsen AK, Eriksen J: Treatment outcome of chronic non-malignant pain patients managed in a Danish multidisciplinary pain centre compared to general practice: a randomised controlled trial. Pain. 2000, 84: 203-211. 10.1016/S0304-3959(99)00209-2.View ArticlePubMedGoogle Scholar
- Peters J, Large RG, Elkind G: Follow-up results from a randomised controlled trial evaluating in- and outpatient pain management programmes. Pain. 1992, 50: 41-50. 10.1016/0304-3959(92)90110-W.View ArticlePubMedGoogle Scholar
- Williams AC, Richardson PH, Nicholas MK, Pither CE, Harding VR, Ridout KL, Ralphs JA, Richardson IH, Justins DM, Chamberlain JH: Inpatient vs. outpatient pain management: results of a randomised controlled trial. Pain. 1996, 66: 13-22. 10.1016/0304-3959(96)02996-X.View ArticlePubMedGoogle Scholar
- Deardorff WW, Rubin HS, Scott DW: Comprehensive multidisciplinary treatment of chronic pain: a follow-up study of treated and non-treated groups. Pain. 1991, 45: 35-43. 10.1016/0304-3959(91)90162-Q.View ArticlePubMedGoogle Scholar
- Flavell HA, Carrafa GP, Thomas CH, Disler PB: Managing chronic back pain: impact of an interdisciplinary team approach. Med J Aust. 1996, 165: 253-255.PubMedGoogle Scholar
- McCracken LM, Spertus IL, Janeck AS, Sinclair D, Wetzel FT: Behavioral dimensions of adjustment in persons with chronic pain: pain-related anxiety and acceptance. Pain. 1999, 80: 283-289. 10.1016/S0304-3959(98)00219-X.View ArticlePubMedGoogle Scholar
- Dettori JR, Bullock SH, Sutlive TG, Franklin RJ, Patience T: The effects of spinal flexion and extension exercises and their associated postures in patients with acute low back pain. Spine. 1995, 20: 2303-2312.View ArticlePubMedGoogle Scholar
- Jensen MP, Turner JA, Romano JM, Fisher LD: Comparative reliability and validity of chronic pain intensity measures. Pain. 1999, 83: 157-162. 10.1016/S0304-3959(99)00101-3.View ArticlePubMedGoogle Scholar
- Linton SJ, Götestam KG: Relations between pain, anxiety, mood and muscle tension in chronic pain patients. A correlation study. Psychother Psychosom. 1985, 43: 90-95.View ArticlePubMedGoogle Scholar
- Herr KA, Mobily PR, Smith C: Depression and the experience of chronic back pain: a study of related variables and age differences. Clin J Pain. 1993, 9: 104-114.View ArticlePubMedGoogle Scholar
- Vasseljen O, Westgaard RH: Can stress-related shoulder and neck pain develop independently of muscle activity?. Pain. 1996, 64: 221-230. 10.1016/0304-3959(95)00103-4.View ArticlePubMedGoogle Scholar
- Jensen I, Nygren A, Gamberale F, Goldie I, Westerhol P: Coping with long-term muskuloskeletal pain and its consequences: Is gender a factor?. Pain. 1994, 57: 167-172. 10.1016/0304-3959(94)90220-8.View ArticlePubMedGoogle Scholar
- Linssen AC, Spinhoven P: Multimodal treatment programmes for chronic pain: a quantitative analysis of existing research data. J Psychosom Res. 1992, 36: 275-286. 10.1016/0022-3999(92)90092-G.View ArticlePubMedGoogle Scholar
- Bergstrom G, Jensen IB, Bodin L, Linton SJ, Nygren AL, Carlsson SG: Reliability and factor structure of the Multidimensional Pain Inventory – Swedish Language Version: (MPI-S). Pain. 1998, 75: 101-110. 10.1016/S0304-3959(97)00210-8.View ArticlePubMedGoogle Scholar
- Wilkes MS: Chronic back pain: does bed rest help?. West J Med. 2000, 172: 121-10.1136/ewjm.172.2.121.View ArticlePubMedPubMed CentralGoogle Scholar
- Loupasis GA, Stamos K, Katonis PG, Sapkas G, Korres DS, Hartofilakidis G: Seven- to 20-year outcome of lumbar discectomy. Spine. 1999, 24: 2313-2317. 10.1097/00007632-199911150-00005.View ArticlePubMedGoogle Scholar
- Litschi M, Reiss A, Buhler D, Dober S, Jeger P, Luscher C, Neukom S, Willi U, Michel BA, Uebelhart D, Sprott H: Interdisciplinary outpatient pain program (IOPP). Swiss Med Wkly. 2001, 31 (Suppl 126): S24-Google Scholar
- Flor H, Rudy TE, Birbaumer N, Streit B, Schugens MM: Zur Anwendbarkeit des West Haven-Yale Multidimensional Pain Inventory im deutschen Sprachraum. Schmerz. 1990, 4: 82-87.View ArticlePubMedGoogle Scholar
- Rosenstiel AK, Keefe FJ: The use of coping strategies in chronic low back pain patients: relationship to patient characteristics and current adjustment. Pain. 1983, 17: 33-44. 10.1016/0304-3959(83)90125-2.View ArticlePubMedGoogle Scholar
- Tobler A, Fransen J, Huber E, Steiner W: Anwendung des Rehab-Cycles in der klinischen Praxis. Fallbeispiel: suprapatellärer Knieschmerz. Physiotherapie. 2001, 7: 4-11.Google Scholar
- Bullinger M, Kirchberger I: SF-36: Fragebogen zum Gesundheitszustand (Handanweisung). Hogrefe Verlag für Psychologie. 1998, 7:Google Scholar
- Ware JE, Gandeck B, and the IQOLA Project Group: The SF-36 health survey: development and use in mental health research and the IQOLA Project. Int J Mental Health. 1994, 23: 49-73.View ArticleGoogle Scholar
- Waddell G: Occupational low-back pain, illness behavior and disability. Spine. 1991, 16: 683-685.View ArticlePubMedGoogle Scholar
- Huber E, Stoll T, Ehrat B, Hofer HO, Seifert B, Stucki G: Zuverlässigkeit und Normperzentilen einer neuen isometrischen Muskelkraftmessmethode. Physiotherapie. 1997, 2-8.Google Scholar
This article is published under license to BioMed Central Ltd. This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original URL.