W. Cairns S. Smith

The epidemiology of chronic pain in the community

BACKGROUND Chronic pain is recognised as an important problem in the community but our understanding of the epidemiology of chronic pain remains limited. We undertook a study designed to quantify and describe the prevalence and distribution of chronic pain in the community. METHODS A random sample of 5036 patients, aged 25 and over, was drawn from 29 general practices in the Grampian region of the UK and surveyed by a postal self-completion questionnaire. The questionnaire included case-screening questions, a question on the cause of the pain, the chronic pain grade questionnaire, the level of expressed needs questionnaire, and sociodemographic questions. FINDINGS 3605 questionnaires were returned completed. 1817 (50.4%) of patients self reported chronic pain, equivalent to 46.5% of the general population. 576 reported back pain and 570 reported arthritis; these were the most common complaints and accounted for a third of all complaints. Backward stepwise logistic-regression modelling identified age, sex, housing tenure, and employment status as significant predictors of the presence of chronic pain in the community. 703 (48.7%) individuals with chronic pain had the least severe grade of pain, and 228 (15.8%) the most severe grade. Of those who reported chronic pain, 312 (17.2%) reported no expressed need, and 509 (28.0%) reported the highest expressed need. INTERPRETATION Chronic pain is a major problem in the community and certain groups within the population are more likely to have chronic pain. A detailed understanding of the epidemiology of chronic pain is essential for efficient management of chronic pain in primary care.

Hypertensive diseases of pregnancy and risk of hypertension and stroke in later life: results from cohort study

Abstract Objective: To examine the association between hypertensive diseases of pregnancy (gestational hypertension and pre-eclampsia) and the development of circulatory diseases in later life. Design: Cohort study of women who had pre-eclampsia during their first singleton pregnancy. Two comparison groups were matched for age and year of delivery, one with gestational hypertension and one with no history of raised blood pressure. Setting: Maternity services in the Grampian region of Scotland. Participants: Women selected from the Aberdeen maternity and neonatal databank who were resident in Aberdeen and who delivered a first, live singleton from 1951 to 1970. Main outcome measures: Current vital and cardiovascular health status ascertained through postal questionnaire survey, clinical examination, linkage to hospital discharge, and mortality data. Results: There were significant positive associations between pre-eclampsia/eclampsia or gestational hypertension and later hypertension in all measures. The adjusted relative risks varied from 1.13-3.72 for gestational hypertension and 1.40-3.98 for pre-eclampsia or eclampsia. The adjusted incident rate ratio for death from stroke for the pre-eclampsia/eclampsia group was 3.59 (95% confidence interval 1.04 to 12.4). Conclusions: Hypertensive diseases of pregnancy seem to be associated in later life with diseases related to hypertension. If greater awareness of this association leads to earlier diagnosis and improved management, there may be scope for reducing a proportion of the morbidity and mortality from such diseases. What is already known on this topic Much is known about the effect of cardiovascular risks factors that are shared by men and women, but less on those specific to women Retrospective studies, based on patient recall, suggest that hypertension in pregnancy may be associated with increased risk of cardiovascular diseases in later life What this study adds Prospective recording of blood pressure and proteinuria shows that women who experienced raised blood pressure in pregnancy have a long term risk of hypertension Women who experience raise blood pressure in pregnancy have an increased risk of stroke and, to a lesser extent, an increased risk of ischaemic heart disease Long term cardiovascular risks are greater for women who had pre-eclampsia than those who experienced gestational hypertension (hypertension without proteinuria)

A review of chronic pain after inguinal herniorrhaphy.

BackgroundChronic pain was believed to be a recognized but infrequent complication after inguinal hernia repair. Evidence suggests that patients with chronic pain place a considerable burden on health services. However, few scientific data on chronic pain after this common elective operation are available. ObjectivesTo review the frequency of chronic pain and to discuss etiological theories and current treatment options for patients with chronic post herniorrhaphy pain. Materials and MethodsAll studies of postoperative pain after inguinal hernia repair with a minimum follow-up period of 3 months, published between 1987 and 2000, were critically reviewed. Results and DiscussionThe frequency of chronic pain after inguinal hernia repair was found to be as high as 54%, much more than previously reported. Quality of life of these patients is affected. Chronic pain is reported less often after laparoscopic and mesh repairs. Recurrent hernia repair, preoperative pain, day case surgery, delayed onset of symptoms, and high pain scores in the first week after surgery, however, were identified to be risk factors for the development of chronic pain. Definition of chronic pain was not explicit in the majority of the reviewed studies. Accurate evaluation of the frequency of chronic pain will require standardization of definition and methods of assessment. Prospective studies are required to define the role of risk factors identified in this review.

A retrospective cohort study of post mastectomy pain syndrome

Post mastectomy pain syndrome is a condition which can occur following breast surgery and has until recently been regarded as uncommon. Recent reports have suggested that it may affect 20% or more of women following mastectomy. The symptoms are distressing and may be difficult to treat however treatment for neuropathic pain can be successful. This paper reports a retrospective cohort of consecutive mastectomy cases over a six year period in one region of whom 511 survivors were traced and eligible for survey. A total of 408 completed a questionnaire survey which revealed that 175 (43%) had ever suffered from postmastectomy pain syndrome and 119 (29%) reported current symptoms although the majority were decreasing in intensity. A striking finding was the very high cumulative prevalence in younger women (65%) decreasing to 26% in the over 70 year group. The details of the onset, frequency and intensity of symptoms are described along with their natural history. The age effect on the frequency of the syndrome influences the marital status, employment status, housing, and educational status of those who report typical symptoms. Body weight and height are also associated with the frequency of post mastectomy pain syndrome. Relationship between the frequency of post mastectomy pain syndrome and radiotherapy, chemotherapy and the use of tamoxifen are difficult to unravel because of the combinations of pre and post operative treatments received confounded by age. The implications of a much higher frequency of post mastectomy pain are discussed with regard to management and counselling. The high frequency of the syndrome in the younger women is important and possible explanations are explored.

Effects of Weight Loss in Overweight/Obese Individuals and Long-Term Hypertension Outcomes A Systematic Review

Many studies have assessed short-term effects of weight loss on blood pressure, whereas little attention has been paid to long-term effects. We conducted a systematic review to evaluate the long-term effects of weight loss on hypertension outcome measures in adults using literature published from 1966 to 2001. All prospective studies and trials, performed on participants with body mass index of ≥28 kg/m2 with a follow-up of >2 years and weight changes recorded, were included. The data from these studies were used to model the long-term effects on blood pressure. Previous reviews on shorter-term studies indicate a 1:1 drop in blood pressure (mm Hg) with weight loss (kilograms). Our findings, based on studies with follow-up of ≥2 years, demonstrate blood pressure decreases less than this after weight loss. The surgical intervention studies exhibited huge weight losses with undramatic blood pressures changes. When surgical interventions are excluded, the models suggest that for 10 kg weight loss, decreases of 4.6 mm Hg and 6.0 mm Hg in diastolic and systolic blood pressure, respectively, may be expected, about half of that predicted from the short-term trials. Initial blood pressure, the length of follow-up, medication changes, and physiological restrictions may contribute to this reduced effect in the long-term studies. Extrapolation of short-term blood pressure changes with weight loss to the longer term is potentially misleading. The weight/hypertension relationship is complex and needs well-conducted studies with long-term follow-up to examine the effects of weight loss on hypertension outcomes.

Changes in chronic pain severity over time: the Chronic Pain Grade as a valid measure.

&NA; Our understanding of the natural history of chronic pain in the community is limited. This is partly due to the lack of a validated measure of chronic pain severity known to be responsive to change over time. The Chronic Pain Grade questionnaire has been shown to be valid and reliable for use in a general population as a self‐completion questionnaire. However, its reliability and validity for use in longitudinal studies and its responsiveness to change over time has not yet been assessed. We undertook a postal survey designed to test the responsiveness and the validity of the Chronic Pain Grade questionnaire over time. A random sample of 560 chronic pain patients, aged 25 years and over was drawn from an existing cohort and stratified for age, gender and chronic pain severity. Subjects were re‐surveyed by a postal self‐completion questionnaire consisting of the Chronic Pain Grade and the SF‐36 general health questionnaire, which is known to be responsive to change in health over time. To test whether changes in CPG scores correlated with changes in SF‐36 scores, Spearmans rank correlation coefficients were calculated. A response rate of 86% was achieved for the follow‐up study. The majority of SF‐36 scores changed in the hypothesized directions. Changes in CPG scores were significantly correlated with changes in most of the SF‐36 domains. We concluded that the CPG is a useful and valid objective instrument for measuring change in severity of chronic pain over time and could be used in longitudinal studies of chronic pain severity.

Psychological, surgical, and sociodemographic predictors of pain outcomes after breast cancer surgery: A population-based cohort study

Summary Risk factors for chronic pain up to 9 months after breast cancer surgery include younger age, psychological vulnerability, axillary clearance surgery, and severe acute postoperative pain. ABSTRACT Chronic postsurgical pain (CPSP) is a common postoperative adverse event affecting up to half of women undergoing breast cancer surgery, yet few epidemiological studies have prospectively investigated the role of preoperative, intraoperative, and postoperative risk factors for pain onset and chronicity. We prospectively investigated preoperative sociodemographic and psychological factors, intraoperative clinical factors, and acute postoperative pain in a prospective cohort of 362 women undergoing surgery for primary breast cancer. Intraoperative nerve handling (division or preservation) of the intercostobrachial nerve was recorded. At 4 and 9 months after surgery, incidence of chronic painful symptoms not present preoperatively was 68% and 63%, respectively. Univariate analysis revealed that multiple psychological factors and nerve division was associated with chronic pain at 4 and 9 months. In a multivariate model, independent predictors of CPSP at 4 months included younger age and acute postoperative pain (odds ratio [OR] 1.34, 95% confidence interval [CI] 1.12 to 1.60), whereas preoperative psychological robustness (OR 0.70, 95% CI 0.49 to 0.99), a composite variable comprising high dispositional optimism, high positive affect, and low emotional distress, was protective. At 9 months, younger age, axillary node clearance (OR 2.97, 95% CI 1.09 to 8.06), and severity of acute postoperative pain (OR 1.17, 95% CI 1.00 to 1.37) were predictive of pain persistence. Of those with CPSP, 25% experienced moderate to severe pain and 40% were positive on Douleur Neuropathique 4 and Self‐Complete Leeds Assessment of Neuropathic Symptoms and Signs pain scales. Overall, a high proportion of women report painful symptoms, altered sensations, and numbness in the upper body within the first 9 months after resectional breast surgery and cancer treatment.

The Future Incidence of Leprosy: A Scenario Analysis

OBJECTIVE To investigate the impact of the current strategy for the elimination of leprosy on its incidence and to assess the consequences of failure to sustain this strategy. METHODS Scenarios for assessing the impact of the elimination strategy were implemented in a computer simulation program. The scenarios reflected the assumptions made regarding contagiousness, transmission and bacille Calmette-Guerin (BCG) vaccination. The trend in case detection rate for the main countries in which leprosy was endemic during 1985-98 was fitted, and incidence up to 2020 was projected. FINDINGS Owing to the gradual shortening of delays in detection up to 1998, and because of the low relapse rate that occurs with multidrug treatment MDT, incidence is predicted to decrease beyond 2000 in all scenarios. The annual decline was a few per cent higher when favourable assumptions were made about protection and coverage of BCG vaccination. Overall, the predicted annual decline in incidences ranged from 2% to 12%. CONCLUSION The elimination strategy reduces transmission, but the decline may be slow. Relaxation of control after 2005 is unjustified given the uncertainty about the rate of decline and the adverse effects of longer delays in detection. A long-term strategy for leprosy control should be adopted.

Factors related to the onset and persistence of chronic back pain in the community: results from a general population follow-up study

Introduction. We compared the prevalence of chronic back pain (CBP) at two points 4 years apart and examined socio-demographic, health, and pain-related factors associated with its onset and persistence. Method. A random population sample of 2,184 adults was surveyed in 1996 and resurveyed in 2000. The questionnaire included chronic pain case definition questions (pain for 3 months or longer); the cause (1996) or site (2000) of any chronic pain; the Chronic Pain Grade questionnaire; the Level of Expressed Need (LEN) questionnaire; the SF-36 general health questionnaire; and demographic questions. Those with CBP in 1996 and 2000 had “persistent” CBP; those with CBP in 1996 but not 2000 had “recovered” CBP; those with CBP in 2000 but not 1996 had “new” CBP. Results. Corrected response rates were 82.3% (1996) and 83.0% (2000). The sample prevalence of CBP was 16% (1996) and 27% (2000). Factors in 1996 independently associated with “persistent” compared with “recovered” CBP were preexisting arthritis, high LEN, poor mental health, and not living alone. Factors independently predicting “new” CBP compared with no previous CBP were previous chronic pain elsewhere and poor physical health. “Persistent” CBP was associated with more severe pain, higher LEN, and poorer general health than “new” CBP. Discussion. CBP is a common and lasting problem, whose persistence and onset are predicted by clinical (especially pain) and help-seeking behavior factors, rather than socio-demographic. Prevention should focus on these factors.

A clinical prediction rule for nerve-function impairment in leprosy patients

BACKGROUND Nerve-function impairment (NFI) commonly occurs during or after chemotherapy in leprosy and is the key pathological process leading to disability and handicap. We describe the development of a simple clinical prediction rule for estimating the risk of NFI occurrence. METHODS New leprosy cases who presented to a centre in Bangladesh were recruited and followed up for 2 years in a field setting. We used multivariable regression analysis by Coxs proportional hazards model to identify predictive variables for NFI. Discriminative ability was measured by a concordance statistic. Internal validity was assessed with bootstrap resampling techniques. FINDINGS 2510 patients were followed up for 2 years, 166 developed NFI. A simple model was developed with leprosy group (either paucibacillary leprosy [PB] or multibacillary leprosy [MB]) and the presence of any nerve-function loss at registration as predictive variables. Patients with PB leprosy and no nerve-function loss had a 1.3% (95% CI 0.8-1.8%) risk of developing NFI within 2 years of registration; patients with PB leprosy and nerve-function loss, or patients with MB leprosy and no nerve-function loss had a 16.0% (12-20%) risk; and patients with MB leprosy with nerve-function loss had a 65% (56-73%) risk. INTERPRETATION Our prediction rule can be used to plan surveillance of new leprosy patients. Patients at low risk of NFI may need no follow-up beyond their course of chemotherapy (6 months); patients with intermediate risk need a minimum of 1 year of surveillance; and patients with high risk should have at least 2 years of surveillance for new NFI. Current recommendations for surveillance of patients with leprosy (for the duration of chemotherapy only) exclude an important group of patients who are at risk of developing NFI after completion of treatment.