Assessment of chronic pain. II. Problems in the selection of relevant questionnaire items for classification of pain and evaluation and prediction of therapeutic effects

Pain among women: Associations with socio-economic factors over time and the mediating role of depressive symptoms

Background and aims

Lower socioeconomic status (SES), based on economic situation, education and occupation, has been associated with greater morbidity and mortality in a wide range of diseases, and socioeconomic inequalities have been found in several chronic pain populations. Since women are overrepresented in several clinical pain conditions, there is a need to understand the influence of SES among women with pain. In a previous cross-sectional study, socioeconomic-and work conditions were associated with pain among women from the general population of Sweden. In the present study, based on baseline and follow-up measures from 2300 of the same sample, we examined associations between pain variables, socioeconomic status and work conditions over time by means of multiple logistic/linear regression analyses. Additionally, a possible mediating role of depressive symptoms on the relationship between SES and pain was examined.

Methods

The study was a prospective panel survey with two measurements 12 months apart among 2300 women with and without pain from the general population in Stockholm (aged 18–64). Logistic and linear regression analyses were used to identify associations between SES and pain outcomes.

Results

Results revealed that pain is a rather stable condition with large impact on daily functioning among many women. Certain SES variables (educational level, financial strain, occupational level) were related to pain and pain related disability prospectively. Financial strain and to be a blue-collar worker were related to the incidence of pain among all women, while educational level was related to worse pain outcomes among women with pain in terms of pain intensity, pain frequency, number of pain locations and pain-related disability. Symptoms of depression were associated with pain incidence and with pain variables (intensity, number of pain locations and pain-related disability) and with lower SES.

Conclusions

Financial strain and occupational level were here identified as risk factors for the incidence of pain, and could be interpreted as increasing both physical and psychological stress and thereby work both as predisposing the individual to pain and to perpetuate the development of a pain condition. Educational level was associated with the course of pain in terms of pain duration and pain-related disability which may indicate that once affected by pain, lower educational level may be related to less functional coping strategies in the adaptation to the pain condition. Depressive symptoms could be understood as a mediator of the relationship between SES and pain among women in terms of limiting the individual’s strategies to handle pain in a functional manner by increasing passive behavior patterns such as avoidance.

Implications

The interplay between SES and symptoms of depression should be regarded in preventive interventions and in treatment of pain among women. An overall risk-profile in terms of psychosocial and biological factors needs to be assessed early on within pain treatment for women. Increased knowledge of socioeconomic risk factors for long term pain, e.g. low educational level, is needed on all levels among all professionals within the healthcare system in order to facilitate effective communication in the treatment of women with pain.

Burnout among foreign-born and native Swedish women: a longitudinal study

The authors of this study addressed burnout experiences (generally defined as chronic depletion of an individual's energetic resources') over time in relation to other factors (e.g., distress, sleep difficulties, job demands, etc.) among foreign-born women and Swedish native women living in Stockholm. The study design was a longitudinal panel survey with two waves one year apart. In the first wave, 3,616 of 6,000 randomly selected women took part, and 2,300 of the initial 3,616 women also participated in the second wave; 427 were foreign-born women, and 1,873 were Swedish native women. Baseline/emerging distress, emerging sleep difficulties, worsening general social support, job demands at baseline/escalating during the assessment period, emerging unemployment, constraints in social support at work, and sustained/emerging financial strain were associated with future burnout, regardless of background. More foreign-born women than Swedish native women reported burnout, with these differences maintained at one-year follow-up. The factors related to burnout were largely the same in both groups, but smoking and cardiovascular disease were related to burnout only among foreign-born women. Younger age, job demands, and working hours were associated with burnout among Swedish native women. The authors found that the women had concurrent problems such as burnout, distress, and sleep problems, but foreign background was not independently related to burnout.

Pain among women: Associations with socio-economic and work conditions

We examined pain prevalence (general/body sites) and its characteristics/consequences among a randomised sample of women from the general population between 18 and 64 years (n=3,616). We also scrutinised associations between pain and various factors (e.g. socio-economic) by means of multivariate logistic/linear regression analyses. The women completed a questionnaire assessing various areas (e.g. pain). The design was cross-sectional and data were collected during 8 consecutive weeks. Sixty-three per cent of women reported pain during the last 3 months, of which 65% during more than 3 months. The multivariate analyses revealed associations between various socio-economic factors (e.g. financial strain) and pain in general/all studied body sites. In addition, psychosocial work conditions (i.e. work strain and social support) were significantly related to pain. Moreover, the multivariate analyses conducted among women with pain indicated relationships between socio-economic/psychosocial work conditions, and pain characteristics (e.g. intensity) and consequences (i.e. disability). A large number of women from the general population suffer from pain, in particularly prolonged pain. Women in a deprived socio-economic situation not only run a higher pain risk, but also experience their pain as more severe/disabling than their more privileged counterparts. Improvements of, for example, the socio-economic status among women living in deprived social and material circumstances, along with improved working environment may be crucial to reduce women's pain problems.

Psychosocial experiences among primary care patients with and without musculoskeletal pain

We examined differences in demographic/financial characteristics, burnout, job demands/control/strain and symptoms of depression as measured by GHQ among primary care patients with (n=838) and without pain (n=135). In addition, we examined factors associated with the presence of pain by means of logistic regression analyses among all participants, and inter-relations between demographic/financial/pain/health variables, symptoms of depression, burnout, and disability by means of multivariate regression analyses among pain patients. The patients completed a questionnaire about areas such as job strain and burnout. The design was cross-sectional and data were collected during 15 consecutive days. The univariate analyses showed that pain patients, compared with patients without pain, were more often females, older, divorced, foreign-born, had been more often on sick-leave, were more preoccupied with how to make ends meet and had greater difficulties in raising a reasonable sum of money within a specific period of time. In addition, they had greater levels of depression symptoms, burnout, and job strain. However, the multivariate analyses showed that symptoms of depression and burnout were more associated with such variables as sick-leave and divorce than by pain parameters. The logistic regression revealed that the presence of pain was associated with female gender, sick-leave, and high levels of job strain and mean total burnout. Finally, pain patients had a severe clinical situation in terms of, for example, constant, intense, and prolonged pain, and experienced a high degree of disability due to pain. We corroborated previous findings and may have provided new insights into the experiences of pain patients that may be of importance when considering intervention. Although we pointed to some important factors associated with pain, symptoms of depression and burnout, much of their variation remains to be explained. Thus, further research appears necessary, not least concerning the role of burnout as an antecedent to pain.

The role of psychosocial factors in the course of pain--a 1-year follow-up study among women living in Sweden

The understanding of the associations between psychosocial factors and persistent pain and their impact on the course of pain among women is crucial to identify risk populations and prevent long-term pain from developing. The aim of the study was to investigate the course of pain among women and the psychosocial factors associated with it. The study was a 1-year follow-up (FU) among 2,300 women in the general population of Sweden. Sociodemographic and psychosocial factors were analyzed in relation to the course of pain, assessed as the presence of pain during the last 3 months at baseline (BL) and at FU. Thirty-three percent of the women with no pain at BL and 77% of those with pain at BL reported pain at FU. Compared to the pain-free women, those who developed pain at FU reported lower social support and physical quality of life (QoL) and worse mental health. Women with sustained pain were older and reported worse mental health, lack of social support, and lower levels of QoL compared to those who recovered from pain. In the multiple logistic regression analyses, only post-traumatic stress symptoms were associated with the development of pain at FU. Number of pain locations and pain duration at BL and physical QoL were associated with sustained pain. Moreover, social support was identified as a protective factor against sustained pain. Pain is persistent or recurrent in a general female population. The results indicate that psychosocial factors do not work as primary predictors in the course of pain and might be better understood through indirect processes by limiting the individual's resources for handling pain in a functional manner.

Spinal cord stimulation for patients with inoperable chronic critical leg ischemia

BACKGROUND

Because of the prevalence of diabetes, the treatment of diabetic foot is still challenging. Even an exactly proved effective and practical method can't be listed except vascular surgery which is not a long-term way for it. Spinal cord stimulation (SCS) is a very promising option in the treatment algorithm of inoperable chronic critical leg ischemia (CLI).

DATA SOURCES

We searched Pubmed database with key words or terms such as "spinal cord stimulation", "ischemic pain" and "limb ischemia" appeared in the last five years.

RESULTS

The mechanism of SCS is unclear. Two theories have emerged to interpret the benefits of SCS. Pain relief from SCS can be confirmed by a majority of the studies, while limb salvage and other more ambitious improvements have not come to an agreement. The complications of SCS are not fatal, but most of them are lead migration, lead connection failure, and local infection.

CONCLUSIONS

SCS is a safe, promising treatment for patients with inoperable CLI. It is effective in pain reduction compared with traditional medical treatment.

Procedure-related pain among adult patients with hematologic malignancies

BACKGROUND

Cancer patients undergo numerous invasive diagnostic procedures. However, there are only sparse data on the characteristics and determinants for procedure-related pain among adult cancer patients.

METHODS

In this prospective study, we evaluated the characteristics and determinants of procedure-related pain in 235 consecutive hematologic patients (M/F:126/109; median age 62 years, range 20-89 years) undergoing a bone marrow aspiration/biopsy (BMA) under local anesthesia. Questionnaires were used to assess patients before-, 10 min and 1-7 days post BMA. Using logistic regression models, we calculated odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

165/235 (70%) patients reported pain during BMA; 92 (56%), 53 (32%) and 5 (3%) of these indicated moderate [visual analogue scale (VAS)>or=30 mm], severe (VAS>54 mm) and worst possible pain (VAS=100 mm), respectively. On multivariate analyses, pre-existing pain (OR=2.60 95% CI 1.26-5.36), anxiety about the diagnostic outcome of BMA (OR=3.17 95% CI 1.54-6.52), anxiety about needle-insertion (OR=2.49 95% CI 1.22-5.10) and low employment status (sick-leave/unemployed) (OR=3.14 95% CI 1.31-7.55) were independently associated with an increased risk of pain during BMA. At follow-up 10 min after BMA, 40/235 (17%) patients reported pain. At 1, 3, 6 and 7 days post BMA, pain was present in 137 (64%), 90 (42%), 43 (20%) and 25 (12%) patients, respectively.

CONCLUSIONS

We found that 3/4 of hematologic patients who underwent BMA reported procedural pain; one third of these patients indicated severe pain. Pre-existing pain, anxiety about the diagnostic outcome of BMA or needle-insertion, and low employment status were independent risk factors.

Burnout among women: associations with demographic/socio-economic, work, life-style and health factors

This study examined the occurrence of low/high burnout among women and the demographic/socio-economic, work, life-style, and health "correlates" of high burnout. The sample consisted of 6.000 randomly selected women from the general population, of which 3.591 participated. The design was cross-sectional. The univariate analyses showed that about 21% of the women had high burnout, and compared to those with low burnout, they were more often younger, divorced, blue-collar workers, lower educated, foreigners, on unemployment/retirement/sick-leave, financially strained, used more medication and cigarettes, reported higher work demands and lower control/social support at work, more somatic problems (e.g. pain) and depression. The regression analysis showed that only age, sick-leave, financial strain, medication, work demands, depression and somatic ailments were independently associated with high burnout. Thus, women with high burnout were apparently faring poorly financially, emotionally and physically. Considering our findings, interventions to alleviate their problems may be necessary. We may have provided new insights into women's burnout experiences, but longitudinal studies are warranted to firmly identify "determinants" of burnout.

Pain induced by photodynamic therapy of warts

BACKGROUND

Photodynamic therapy with topical 5-aminolevulinic acid (ALA), followed by irradiation with red light (ALA-PDT), is used for non-melanoma skin cancer and other dermatological diseases. Pain during and after light exposure is a well-known adverse advent that may be a limiting factor for treatment, particularly, in viral warts.

METHODS

To assess the pain induced by ALA-PDT, we asked 45 patients enrolled in a randomized, placebo-controlled trial with six consecutive ALA- and placebo-PDT treatments for recalcitrant foot and hand warts to fill in questionnaires about pain immediately and 24 h after each treatment.

RESULTS

Immediately and 24 h after each of the six treatments, pain intensity was significantly higher in warts treated with ALA-PDT than in warts treated with placebo-PDT (P<0.028). Severe or unbearable pain was reported from a median of 17% (6-31%) of the ALA -treated warts and from a median of 2% (0-15%) from the placebo-treated warts immediately after the treatments. With increasing treatments, no significant change in pain intensity was observed and no significant relation was found between the pain intensity and the relative change in wart area. The pain was primarily characterized as burning and shooting. The pain lasted about 30 h (range: 1-96 h).

CONCLUSION

We conclude that pain induced by ALA-PDT is of such intensity in about one-fifth of the warts that pain relief is indicated.

The stress of musculoskeletal pain: a comparison between primary care patients in various ages

OBJECTIVES

To analyse differences in demographic/financial/pain/health variables, disability, General Health Questionnaire (GHQ; i.e., depression symptoms) and coping among 949 primary care pain patients in various ages (20-65+ years) and to identify predictors of disability and coping.

METHOD

Patients completed scales about various areas (e.g., coping). The design was cross-sectional and data were collected during 15 consecutive days at 20 randomly selected primary care centres in Stockholm.

RESULTS

Univariate analyses showed that older patients (a) were more often divorced, blue-collar workers, less educated and had greater difficulties with living expenses, (b) had pain of longer duration, more frequently and of more complexity, and felt more disabled, (c) consumed more painkillers, analgesics, sedatives and other medications, had received more pain treatments and had more health problems and (d) more often used passive coping for pain. Younger patients (a) had more severe pain, were financially strained and were more often unemployed and (b) more often used active coping for pain. There were no significant differences concerning GHQ scores. Multivariate regression analyses showed that active coping was associated with younger age. High disability and passive coping were associated with older age.

CONCLUSION

We corroborated previous findings and may provide new insights into the experiences of older and younger pain patients. Further research concerning, for example, the elderly at risk of developing pain problems is needed.

Pain questionnaires in the analysis of long lasting (chronic) pain conditions

A study on mainly non-cancer-related pain patients was performed concerning clinical patient data used for pain history-taking and diagnosis. More than 2100 consecutive patients referred to the anaesthetic branch of the Multidisciplinary Pain Centre (MPC) were evaluated at the first visit. The use of a paper questionnaire, including a pain-drawing and pain intensity Visual Analogue Scale (VAS), was analysed. In a substudy of more than 290 consecutive patients, data from a computerised questionnaire and database was analysed. The European Organization for Research and Treatment of Cancer Quality of Life Questionnaires (EORTC QLQ-C30) (version 2.0) was used for recording of the Global Health Status/Quality of Life (GHS/QoL) score. The substudy also included the summarized mechanism-based evaluation of the patients at the first visit, judged by a specialist in pain medicine. The patients' GHS/QoL score was low. The most important pain mechanisms, were nociceptive and peripheral neurogenic. The clinical use of these tools for patient evaluation and for the choice of treatment is suggested. Information technology may be used for analysis of descriptive, evaluative, predictive and prognostic data in pain patients. It can also be used as a tool for clinical pain research towards a mechanism-based evaluation. Evaluation of patient quality of life and function is suitable for outcome research.

Age and musculoskeletal pain

Using questionnaires, we analyzed associations between different pain variables (e.g., pain intensity) and age (20-65+ years) among 949 primary pain patients. Older patients (a) were more often divorced, were blue-collar workers, were less educated, and had greater difficulties with living expenses; (b) had pain of longer duration, more frequently and of more complexity, and felt more disabled; (c) consumed more painkillers, analgesics, sedatives, and other medications, and had received more pain treatments; and (d) had more health problems. Younger patients had more severe pain, were financially strained, and were more often unemployed. A multivariate regression analysis showed that high disability was more determined by older than young age. However, other factors (e.g., pain complexity) were also important. Thus, older and younger patients experienced their pain differently

Pain and quality of life in patients with critical limb ischaemia: results of a randomized controlled multicentre study on the effect of spinal cord stimulation. ESES study group

We carried out an assessment of pain and quality of life of patients with critical limb ischaemia during the follow-up of a multicentre randomized trial in more detail than previously reported. In a multicentre clinical trial 120 patients were randomized between medical treatment and medical treatment plus spinal cord stimulation. Patients were selected on the basis of clinical symptoms and macrocirculatory data as described in the European consensus document on critical limb ischaemia. Data were collected at intake and then 1, 3, 6, 12 and 18 months later. Primary outcome measures were limb salvage, pain relief and quality of life. Patient and limb survival was estimated with the Kaplan-Meier method. Pain was evaluated using the visual analogue scale (VAS), the McGill pain questionnaire, the pain score of the Nottingham Health Profile (NHP) and the use of analgesics. Quality of life was evaluated using the NHP, the EuroQol and mobility subscore of the Sickness Impact Profile. The 2-year limb survival was 52% for SCS treatment and 46% for standard treatment (p =0.47). Pain relief was considerable in both treatment strategies (p<0.005) with no significant differences between the strategies. The improvement occurred within the first few months and remained stable during further follow-up. Patients with SCS used fewer non-narcotic and narcotic drugs (p<0.001 at t=1 and t=3, p<0.002 at t=6). The overall scores of quality of life improved significantly (p<0.05), with no difference in score between treatments. The subscores of mobility and energy of the NHP in non-amputated patients was significantly better in the SCS group (p<0.005). Amputation had a negative effect on mobility, resulting in a difficult rehabilitation but relieved pain substantially (p<0. 05). In contrast to the existing literature, the randomized trial revealed no major difference in overall pain and quality of life assessment between treatment groups. The effect on energy and mobility was significantly better in patients treated with SCS, who also used substantially fewer analgesics.

Neuropathic pain in cancer patients: mechanisms, syndromes, and clinical controversies

The identification of a neuropathic pain syndrome in a cancer patient requires a focused clinical evaluation based on knowledge of common neuropathic pain syndromes. If a tumor is directly involved in the etiology of the pain, oncologic treatment is an initial consideration and may include surgery, radiation, or chemotherapy. There is no single accepted algorithm for the analgesic treatment of neuropathic pain and a systematic approach utilizing therapeutic trials of specific agents at gradually increasing doses is warranted. A trial of opioids, perhaps in combination with an NSAID, is warranted. If the pain is relatively unresponsive to an opioid, a trial with an adjuvant analgesic is reasonable. For example, a tricyclic antidepressant might be selected early for patients with continuous dysesthesia, and early treatment with an anticonvulsant might be used if the pain is predominantly lancinating or paroxysmal. Other adjuvant analgesics can be selected if there is insufficient response to these agents. A trial of sympathetic blockade, pharmacologic, anesthetic or surgical, should be considered in patients with evidence of causalgia or reflex sympathetic dystrophy. Physiatric modalities such as massage, heat, or cold; counterstimulation or transcutaneous electrical nerve stimulation (TENS), and orthopedic interventions, such as braces and splints may be useful. Epidural injections or neurostimulation of the spinal cord or brain can be considered in selected cases where appropriate expertise is available. Treatment of neuropathic pain remains a challenge for both clinicians and patients. The complexity of syndromes and underlying etiologic mechanisms warrants further clinical trials to determine the best treatment modalities for individual pain syndromes.

Priority setting with regard to placement on waiting list to a pain clinic. The feasibility of a delegated ranking procedure

Short waiting periods for all patients referred to a pain clinic is desirable but ordinarily not possible. In a questionnaire, 25% of the Swedish anaesthetic pain clinics reported a waiting list exceeding 6 months. The long waiting-time shows that some kind of priority setting is necessary. The aim of the present investigation was to study the feasibility of a rational priority setting based on a ranking procedure. Secretary and nurse priority ranked patients according to a system utilizing the physician's referral and a questionnaire completed by the patient. These priority ratings were compared to the final ranking by the doctor which was done after an interview without access to the questionnaire. The results of the present investigation show that the secretary as well as two nurses generally 'overestimated' the patients' pain problems compared with the priority made by the doctor. However, 12 out of 142 patients' problems were 'underestimated' but this was deemed to increase risk in only one case. The possible risks with a delegated ranking procedure have, however, to be judged against the disadvantages of no priority setting at all and the advantages of a rational use of staff members. This experiment has indicated the feasibility of a delegated ranking procedure.

Clinical features of the failed-back syndrome

This study comprises 78 patients who were treated for chronic back pain at a multidisciplinary, multimodal pain treatment center. These patients were selected from 494 patients examined by the authors because all of their previous medical records, operative notes, and imaging studies were available for review. The records and imaging studies were reviewed independently by a neurosurgeon and an orthopedist, and a retrospective decision was made concerning the historical and physical findings correlated with imaging studies in order to provide justification for the intervention. At the time of admission to the pain treatment center, 16 patients had no physical abnormalities that would explain their back complaint and 16 patients exhibited minor postoperative changes insufficient to cause disabling pain. Twenty-seven patients suffered from a complication of previous surgery, 13 had spondylotic disease, and in six a new diagnosis was established. Comprehensive psychiatric evaluation of the 78 patients revealed that 10 patients had a definitive psychiatric diagnosis, 34 were diagnosed as having a maladaptive personality disorder, and 34 had a normal pre-pain personality. Sixty-seven patients suffered from reactive depression. Fifty-four patients were taking medications at doses higher than usually prescribed, 58 misused narcotics, nine had drug addiction, and 54 were suffering withdrawal symptoms. Of the 78 patients, 64 underwent a total of 171 operations, an average of 2.6 per patient. The authors applied the clinical criteria approved by the American Association of Neurological Surgeons and the American Academy of Orthopedic Surgeons for selection of surgery or chemonucleolysis in the treatment of the herniated disc to these patients. Preoperative imaging studies were normal or demonstrated nonspecific degenerative disc disease in 52 patients. Twenty-six patients had a diagnosis based on radiological findings that warranted surgery. Clinical criteria justifying intervention were met in 25 patients and not met in 53. Imaging and clinical criteria for a second operation were met in 18 (40%) of the patients. After the second operation all patients met the criteria: subsequent surgery was necessary to treat effects of an earlier operation in 73%. These data indicate that many of these patients with failed-back syndrome underwent an original operation based on a persistent complaint of pain, frequently coupled with an underlying psychiatric abnormality, although they did not meet the criteria generally accepted by neurosurgeons for intervention at the time of first surgery.

Lack of analgesic effect of opioids on neuropathic and idiopathic forms of pain

The aim of the present study has been to assess the responsiveness of various types of chronic pain to opioids given i.v. and tested against placebo in a double-blind, randomized fashion. Pain classified as primary nociceptive was effectively alleviated (P greater than 0.001) while neuropathic deafferentation pain was not significantly influenced by morphine or equivalent doses of other opioids. Also 'idiopathic' pain, defined as chronic pain with no or little demonstrable pathology, failed to respond. The results were not related to whether the patients were regular users of narcotic analgesics or not. The outcome of our double-blind opioid test has proved useful to justify a continued, or discontinued, use of narcotic medication in individual patients. It may also support the indication and choice of invasive stimulation procedures (spinal cord or brain). The results of the study illustrate the misconception of chronic pain as an entity and highlight the importance of recognizing different neurobiological mechanisms and differences in responsiveness to analgesic drugs as well as to non-pharmacological modes of treatment. The opioid test has thus become a valuable tool in pain analysis and helpful as a guide for further treatment.

Personality characteristics of patients with chronic pain in comparison with normal controls and depressed patients

The Karolinska Scales of Personality (KSP) were used for the description of self-reported personality characteristics in pain patients. The patients were a selected group, suffering from chronic non-malignant pain mainly of neurological origin, and had in all cases an established somatic diagnosis. In comparison with normal controls, the pain patients differed only with respect to two KSP scales, showing significantly more negative childhood experiences and less Inhibition of Aggression than the normals. In contrast, there were several and pronounced differences between the pain patients and two psychiatric groups with depressive disorders, one with and one without pain. Thus this group of chronic pain patients did not show the personality characteristics predisposing for depressive disorders. Furthermore, the KSP personality factors were found to be related to variables describing consequences of the pain, but the power of the KSP to predict the outcome of the pain treatment appeared to be limited. The KSP appears to have several advantages in comparison, e.g., with the Minnesota Multiphasic Personality Inventory, the most frequently used method for the assessment of chronic pain patients. Unlike the MMPI, the KSP reflects aspects of personality and is not primarily a measure of psychopathology. In addition, the KSP is more up-to-date and its completion is less time-consuming. The usefulness of the KSP for the assessment of chronic pain patients deserves therefore further examination.