Chronic widespread pain predicts physical inactivity: results from the prospective EPIFUND study

This study tested the hypothesis that chronic widespread pain (CWP) would predict low levels of physical activity (PA). Pain status and PA levels were ascertained at baseline and 32 months in community subjects. Three PA questions were used: "in comparison with others your own age, is your PA "the same" (referent), "more-much more" or "less-much less"", and "during the past month on average how many days/week have you taken exercise that has (i) lasted at least 20 min? and (ii) made you sweat?: "4-7" (referent), "1-3" or "none"". Multinomial logistic regression models quantified the relationship between baseline CWP and PA at follow-up (relative risk ratios (RRR) (95% confidence intervals)). Two thousands one hundred and eighty-two subjects participated and provided complete pain and PA information at both timepoints. CWP was reported by 18% (n=429) of participants at baseline. Compared to subjects who were free of CWP at baseline, those with CWP had an increased odds of reporting "less-much less" PA at follow-up (RRR=4.5 (3.2-6.2)). This relationship remained after adjustment for confounders (RRR=1.9 (1.3-2.9)). A similar association was observed with exercise that lasted at least 20 min (RRR=1.9 (1.3-2.8)). The current study suggests that low self-reported levels of physical activity are a consequence of having CWP.

Risk factors for onset of chronic oro-facial pain--results of the North Cheshire oro-facial pain prospective population study

Due to the cross-sectional nature of previous studies, whether mechanical factors predict the onset of Chronic oro-facial pain remains unclear. Aims of the current study were to test the hypotheses that self-reported mechanical factors would predict onset of Chronic oro-facial pain and that any observed relationship would be independent of the confounding effects of psychosocial factors and reporting of other unexplained symptoms. About 1735 subjects who had completed a baseline questionnaire were assessed at 2year follow-up for the presence of Chronic oro-facial pain, psychosocial factors (anxiety and depression, illness behaviour, life stressors and reporting of somatic symptoms), mechanical dysfunction (facial trauma, grinding, phantom bite and missing teeth) and reporting of other unexplained symptoms (chronic widespread pain, irritable bowel syndrome and chronic fatigue). About 1329 subjects returned completed questionnaires (adjusted response rate 87%). About 56 (5%) reported new episodes of Chronic oro-facial pain at follow-up. Univariate analyses showed that age, gender, reporting of other unexplained symptoms, psychosocial factors and two self-report mechanical factors predicted the onset of Chronic oro-facial pain. However multivariate analysis showed that mechanical factors did not independently predict onset. The strongest predictors were health anxiety (Relative Risk (RR) 2.8, 95% CI 1.3-6.2), chronic widespread pain (RR 4.0 95% C.I. 2.2-7.4) and age (RR 0.2, 95% CI 0.1-0.7). The findings from this prospective study support the hypothesis that psychosocial factors are markers for onset of Chronic oro-facial pain. The efficacy of early psychological management of Chronic oro-facial pain to address these factors should be a priority for future investigations.

Do genetic predictors of pain sensitivity associate with persistent widespread pain?

Genetic risk factors for pain sensitivity may also play a role in susceptibility to chronic pain disorders, in which subjects have low pain thresholds. The aim of this study was to determine if proposed functional single nucleotide polymorphisms (SNPs) in the GTP cyclohydrolase (GCH1) and μ opioid receptor (OPRM1) genes previously associated with pain sensitivity affect susceptibility to chronic widespread pain (CWP). Pain data was collected using body manikins via questionnaire at three time-points over a four year period from subjects aged 25-65 in the North-West of England as part of a population based cohort study, EPIFUND. CWP was defined at each time point using standard criteria. Three SNPs forming a proposed "pain-protective" haplotype in GCH1 (rs10483639, rs3783641 and rs8007267) and two SNPs in OPRM1 (rs1777971 (A118G) and rs563649) were genotyped in cases with persistent CWP (CWP present at ≥2 time-points) and controls who were pain-free at all time-points. The expectation-maximisation algorithm was used to estimate haplotype frequencies. The frequency of the "pain-protective" (CAT - C allele of rs10483639, A allele of rs3783641 and T allele of rs8007267) haplotype was compared to the frequency of the other haplotypes between cases and controls using the χ² test. Allele frequencies and carriage of the minor allele was compared between cases and controls using χ² tests for the OPRM1 SNPs. The frequency of the proposed GCH1 "pain-protective" haplotype (CAT) did not significantly differ between cases and controls and no significant associations were observed between the OPRM1 SNPs and CWP. In conclusion, there was no evidence of association between proposed functional SNPs, previously reported to influence pain sensitivity, in GCH1 and OPRM1 with CWP. Further evidence of null association in large independent cohorts is required to truly exclude these SNPs as genetic risk factors for CWP.

Genetic variation in the hypothalamic-pituitary-adrenal stress axis influences susceptibility to musculoskeletal pain: results from the EPIFUND study

OBJECTIVES

To determine if genetic variation in genes in the hypothalamic-pituitary-adrenal (HPA) axis, the primary stress response system, influences susceptibility to developing musculoskeletal pain.

METHODS

Pain and comorbidity data was collected at three time points in a prospective population-based cohort study. Pairwise tagging single nucleotide polymorphisms (SNPs) were selected and genotyped for seven genes. Genetic association analysis was carried out using zero-inflated negative binomial regression to test for association between SNPs and the maximum number of pain sites across the three time points in participants reporting pain, reported as proportional changes with 95% CIs. SNPs were also tested for association with chronic widespread pain (CWP) using logistic regression reporting odds ratios and 95% CI.

RESULTS

A total of 75 SNPs were successfully genotyped in 994 participants including 164 cases with persistent CWP and 172 pain-free controls. Multiple SNPs in SERPINA6 were associated with the maximum number of pain sites; for example, each copy of the T allele of rs941601 was associated with having 16% (proportional change=1.16, 95% CI 1.04 to 1.28, p=0.006) more pain sites compared to participants with the CC genotype. SERPINA6 gene SNPs were also associated with CWP. Significant associations between the maximum number of pain sites and SNPs in the CRHBP and POMC genes were also observed and a SNP in MC2R was also associated with CWP. Associations between SNPs and comorbidity of poor sleep quality and depression explained some of the associations observed.

CONCLUSIONS

Genetic variation in HPA axis genes was associated with musculoskeletal pain; however, some of the associations were explained by comorbidities. Replication of these findings is required in independent cohorts.

What characterizes persons who do not report musculoskeletal pain? Results from a 4-year Population-based longitudinal study (the Epifund study)

OBJECTIVE

To identify and characterize persons in the population who do not report musculoskeletal pain.

METHODS

This was a population-based 4-year prospective longitudinal study by postal questionnaire. Population sample recruited from general practice registers in North-West England followed up at 15 months and 4 years.

RESULTS

Of respondents, 17.4% [95% confidence interval (CI) 16.1%-19.7%] reported no pain in the previous month at all 3 measurement intervals over 4 years. They were characterized by low levels of psychological distress [relative risk (RR) low vs high levels of psychological distress 2.3; 95% CI 1.7-2.9], low levels of depression (2.7; 95% CI 2.0-3.6), low levels of anxiety (2.1; 95% CI 1.6-2.7), low health anxiety (1.6; 95% CI 1.2-2.1), and low illness behavior scores (5.8; 95% CI 4.0-8.3), good quality sleep (3.4; 95% CI 2.6-4.4), no somatic symptoms (RR 0 vs 3 or more, 3.1; 95% CI 1.6-6.3) and no adverse life events in the 6 months prior to baseline data collection (RR 0 vs 3 or more, 3.2; 95% CI 1.6-6.2). On multivariable analysis, good quality sleep, low illness behavior, low psychological distress, and absence of recent adverse life events remained statistically independent predictors of musculoskeletal health. In total, 46% of persons who had all 4 of these characteristics consistently reported being free of pain, compared to only 5% of those who had none.

CONCLUSION

In a general population sample, over a period of 4 years, only around 1 in 6 persons do not report musculoskeletal pain. These persons report low levels of psychological distress and high quality sleep, both of which are potentially modifiable risk factors for the targeting of interventional or preventive strategies.

Insecure attachment style is associated with chronic widespread pain

Individuals with “insecure” adult attachment styles have been shown to experience more pain than people with secure attachment, though results of previous studies have been inconsistent. We performed a cross-sectional study on a large population-based sample to investigate whether, compared to pain free individuals, subjects with chronic widespread pain were more likely to report insecure adult attachment style. Subjects in a population-based cross-sectional study completed a self-rated assessment of adult attachment style. Attachment style was categorised as secure (i.e., normal attachment style); or preoccupied, dismissing or fearful (insecure attachment styles). Subjects completed a pain questionnaire from which three groups were identified: pain free; chronic widespread pain; and other pain. Subjects rated their pain intensity and pain-related disability on an 11 point Likert scale. Subjects (2509) returned a completed questionnaire (median age 49.9 years (IQR 41.2–50.0); 59.2% female). Subjects with CWP were more likely to report a preoccupied (RRR 2.6; 95%CI 1.8–3.7), dismissing (RRR 1.9; 95%CI 1.2–3.1) or fearful attachment style (RRR 1.4; 95%CI 1.1–1.8) than those free of pain. Among CWP subjects, insecure attachment style was associated with number of pain sites (Dismissing: RRR 2.8; 95%CI 1.2–2.3, Preoccupied: RRR = 1.8, 95%CI 0.98–3.5) and degree of pain-related disability (Preoccupied: RRR = 2.1, 95%CI 1.0–4.1), but not pain intensity. These findings suggest that treatment strategies based on knowledge of attachment style, possibly using support and education, may alleviate distress and disability in people at risk of, or affected by, chronic widespread pain.

Musculoskeletal pain is associated with a long-term increased risk of cancer and cardiovascular-related mortality

OBJECTIVES

To test the hypothesis that individuals with regional and widespread pain disorders have an increased risk of mortality.

METHODS

We conducted a prospective cohort study of 4515 adults. Subjects were an age- and sex-stratified sample who had participated in a population study of pain occurrence during 1996. Based on those reports subjects were classified as having no pain, regional pain or widespread pain. All subjects were identified on the National Health Service Central Register and followed up until April 2005, a total of 8.2 yrs, at which time information was obtained on vital status, and if applicable, date and cause of death. The relationship between pain status and subsequent death is expressed as mortality rate ratios with 95% CIs, adjusted for age, gender, ethnicity and practice.

RESULTS

A total of 35.2% reported regional pain and 16.9% satisfied criteria for widespread pain. In comparison with those without pain, there was a 20% and 30% increased risk of dying over the follow-up period among subjects with regional and widespread pain, respectively. The specific causes of death in excess were cancer and cardiovascular disease. In addition, the mortality risk from both cancer and cardiovascular deaths was found to increase as the number of pain sites that subjects reported increased.

CONCLUSIONS

This study supports a previous observation that persons with regional and widespread pain are at an increased risk of cancer death. Possible mechanisms should be explored.

Restorative sleep predicts the resolution of chronic widespread pain: results from the EPIFUND study

Objectives. Poor sleep is associated with chronic widespread pain (CWP). Conversely, good-quality sleep may play a role in the resolution of pain symptoms. Sleep is a multidimensional construct, comprising a number of diverse components. The aims of the current study were to examine the hypotheses that: (i) good sleep quality would predict the resolution of CWP, (ii) restorative sleep would predict the resolution of CWP and (iii) that these relationships would be independent of confounding psychological factors.

Methods. Subjects in a population-based prospective study completed a pain questionnaire at baseline from which subjects with CWP were identified. Baseline sleep was measured using the Estimation of Sleep Problems Scale which measures sleep onset, maintenance, early wakening and restorative sleep. The questionnaire also contained scales examining psychosocial status. Subjects were followed up 15 months later and pain status was assessed.

Results. A total of 1061 subjects reported CWP at baseline of whom 679 (75% of eligible subjects) responded at follow-up. Of those, a total of 300 (44%) no longer satisfied criteria for CWP. Univariate analysis revealed that three of the four sleep components were associated with the resolution of CWP: rapid sleep onset, odds ratio (OR) = 1.7, 95% CI 1.2, 2.5; absence of early wakening, OR = 1.6, 95% CI 1.1, 2.4; and restorative sleep, OR = 2.7, 95% CI 1.5, 4.8. After adjusting for the effect of psychosocial factors, which may have confounded the relationship, only restorative sleep (OR = 2.0, 95% CI 1.02, 3.8) was associated.

Conclusions. Self-reported restorative sleep was independently associated with the resolution of CWP and return to musculoskeletal health.

The association between neighbourhood socio-economic status and the onset of chronic widespread pain: results from the EPIFUND study

Background

Cross-sectional studies have reported an inverse relationship between socio-economic status and the prevalence of chronic widespread pain (CWP). However, the extent to which this relationship is explained by psychological factors is unknown. The aim of this study was to examine the hypothesis that socio-economic status predicts the onset of CWP but that this relationship would be explained by psychological factors.

Methods

Subjects from three diverse socio-economic areas were recruited into a population-based prospective survey of pain. Subjects completed a questionnaire at baseline that assessed pain status and psychological factors and occupation. Fifteen months later subjects completed a follow-up questionnaire which assessed pain status.

Results

A total of 3489 subjects were free of CWP at baseline and eligible for follow-up, of whom 2782 (79.7%) participated. Of those, 281 (10%) subjects were classified as having new CWP. Logistic regression analysis revealed that compared to subjects from the most affluent socio-economic area, those from the moderate and least affluent areas were respectively, 1.47 (95% CI: 1.08–2.01) and 1.35 (95% CI: 1.00–1.82) times more likely to have new CWP. However, in a stepwise multivariate logistic regression analysis, controlling for psychological factors, the relationship between new onset CWP and socio-economic status was no longer evident.

Conclusions

This study has demonstrated that socio-economic status is related to new onset CWP, but the association is explained by psychological factors. Understanding the factors underlying the association between socio-economic status and pain should help to design intervention strategies which may reduce the burden of chronic pain in identified high risk population groups.

Psychosocial risk markers for new onset irritable bowel syndrome--results of a large prospective population-based study

Irritable bowel syndrome (IBS) affects up to 22% of the general population. Its aetiology remains unclear. Previously reported cross-sectional associations with psychological distress and depression are not fully understood. We hypothesised that psychosocial factors, particularly those associated with somatisation, would act as risk markers for the onset of IBS. We conducted a community-based prospective study of subjects, aged 25-65 years, randomly selected from the registers of three primary care practices. Responses to a detailed questionnaire allowed subjects' IBS status to be classified using a modified version of the Rome II criteria. The questionnaire also included validated psychosocial instruments. Subjects free of IBS at baseline and eligible for follow-up 15 months later formed the cohort for this analysis (n=3732). An adjusted participation rate of 71% (n=2456) was achieved at follow-up. 3.5% (n=86) of subjects developed IBS. After adjustment for age, gender and baseline abdominal pain status, high levels of illness behaviour (odds ratio (OR)=5.2; 95% confidence interval (95% CI) 2.5-11.0), anxiety (OR=2.0; 95% CI 0.98-4.1), sleep problems (OR=1.6; 95% CI 0.8-3.2), and somatic symptoms (OR=1.6; 95% CI 0.8-2.9) were found to be independent predictors of IBS onset. This study has demonstrated that psychosocial factors indicative of the process of somatisation are independent risk markers for the development of IBS in a group of subjects previously free of IBS. Similar relationships are observed in other "functional" disorders, further supporting the hypothesis that they have similar aetiologies.

Epidemiology of chronic musculoskeletal pain

The rate of musculoskeletal pain in adolescent and adult populations is examined, with a focus on three commonly reported pain disorders: shoulder pain, low back pain and fibromyalgia/chronic widespread pain. There is a paucity of data on musculoskeletal pain in adolescent populations. Those studies available suggest that pain is common, although the actual rates are unclear. This is probably due to differences in study methodologies and populations. Pain is commonly reported among adult populations, with almost one fifth reporting widespread pain, one third shoulder pain, and up to one half reporting low back pain in a 1-month period. The prevalence of pain varies within specific population subgroups; group factors (including socioeconomic status, ethnicity and race) and individual factors (smoking, diet, and psychological status) are all associated with the reporting of musculoskeletal pain. However, the precise nature of these relationships, and particularly the mechanisms of association, are unclear and require further investigation.

Is the report of widespread body pain associated with long-term increased mortality? Data from the Mini-Finland Health Survey

OBJECTIVE

To determine whether an observation in a UK study, that persons with chronic widespread pain are at long-term increased risk of cancer mortality, can be replicated in a different setting.

METHODS

Subjects were participants aged >or=30 yrs in the Mini-Finland Health Survey conducted between 1979 and 1980. Information collected included prevalent pains at different joints throughout the body, demographic, anthropometric, lifestyle and occupational factors. During follow-up, until 1994, information on vital status and cause of death was obtained.

RESULTS

7182 persons participated (89.8%). The prevalence of widespread body pain (pain at four or more sites) was 20% in females and 12% in males, and during follow-up there were a total of 1647 deaths. The risk of death was not elevated amongst those with widespread pain [relative risk (RR): 0.86; 95% confidence interval (CI): 0.74-1.00], and in particular, those with widespread pain were at a slightly lower risk of several disease-specific causes of death and cancer death (RR: 0.64; 95% CI: 0.46-0.91).

CONCLUSIONS

This study of multiple pains has not confirmed a previous observation of an association between the reporting of widespread pain and subsequent increased risk of cancer death. Differences in the definitions used or, more probably, the population studied, in particular, a larger rural population with more multiple pains related to physical activity may account for the differences.

Development and validation of classification criteria for idiopathic orofacial pain for use in population-based studies

AIM

To develop and validate a questionnaire-based tool which would enable classification of idiopathic orofacial pain in the general population.

METHODS

A postal questionnaire-based cross-sectional survey was made of 4200 randomly selected adults who were registered with a general medical practice in North West England. The questionnaire collected information on a number of factors: demographics (age, gender), orofacial pain (duration, descriptors, site, pattern, intensity, disability, and consultation behavior), and comorbidities (reporting of other unexplained symptoms and psychosocial factors). Subjects reporting orofacial pain were interviewed by an examiner blinded to their exposure status and classified into 1 of 3 categories: (a) dentoalveolar, (b) musculoligamentous/soft tissue, and (c) idiopathic orofacial pain.

RESULTS

A high adjusted response rate of 72% was achieved (crude response rate 60%). Of those who reported orofacial pain and were eligible for interview (n=218), 197 (88%) were interviewed. Subjects classified by interview into the idiopathic category were more likely to report aching, nagging, and chronic pain pain at multiple sites. They were also more likely to report facial trauma and other chronic symptoms and to have consulted multiple health-care workers. Variables that most strongly predicted membership into the idiopathic category were female gender, nagging, aching pain which was worse when stressed, and topography (pain at multiple sites and unilateral pain).

CONCLUSION

The classification criteria developed for idiopathic orofacial pain can be used as a screening tool for subjects with this condition in the general population.

The role of psychosocial factors in predicting the onset of chronic widespread pain: results from a prospective population-based study

OBJECTIVE

Chronic widespread pain (CWP) is strongly associated with psychosocial distress both in a clinical setting and in the community. The aim of this study was to determine the contribution of measures of psychosocial distress, health-seeking behaviour, sleep problems and traumatic life events to the development of new cases of CWP in the community.

METHODS

In a population-based prospective study, 3171 adults aged 25-65 yrs free of CWP were followed-up 15 months later to identify those with new CWP. Baseline data were available on their scores from a number of psychological scales including Illness Attitude Scales (IAS), Somatic Symptom Checklist (SSC), Hospital Anxiety & Depression Scale, Sleep Problems Scale, and Life Events Inventory.

RESULTS

324 subjects [10%, 95% confidence interval (CI) 9.2, 11.3] developed new CWP at follow-up. After adjustment for age and sex, three factors independently predicted the development of CWP: scoring three or more on the SSC [odds ratio (OR) 1.8, 95% CI 1.1, 3.1], scoring eight or more on the Illness Behaviour subscale of the IAS (OR 3.3, 95% CI 2.3, 4.8), and nine or more on the Sleep Problem Scale (OR 2.7, 95% CI 1.6, 3.2). Subjects exposed to all three factors were at 12 times the odds of new CWP than those with low scores on all scales.

CONCLUSION

Subjects are at substantial increased odds of developing CWP if they display features of somatization, health-seeking behaviour and poor sleep. Psychosocial distress has a strong aetiological influence on CWP.

Pressure pain thresholds and tender point counts as predictors of new chronic widespread pain in somatising subjects

BACKGROUND

Tender points are a general measure of distress both in the community and in clinic subjects. It has been suggested that multiple tender points should be regarded as the early stages of somatisation of distress. Similarly, recent evidence suggests that chronic widespread pain (CWP) is one manifestation of the somatisation of distress.

OBJECTIVE

Given that a high tender point count and CWP are clinical hallmarks of the fibromyalgia syndrome, it was hypothesised that in somatising subjects, a high tender point count or a low pain threshold would predict the development of CWP in the future.

METHODS

In this population-based prospective study, 245 adults aged 25-65 years, free of CWP, were identified on the basis of a detailed questionnaire on pain and a psychosocial questionnaire comprising the Somatic Symptom Checklist and the Illness Behaviour subscale of the Illness Attitude Scales. These subjects took part in a pain threshold examination with a Fischer pressure algometer. Tender point counts were computed by including all areas with a pain threshold<4 kg/cm2. Individuals were followed up at 15 months, at which time 231 (93% of subjects still living at their baseline address) provided data on pain status, using the same instruments.

RESULTS

At follow-up, 26 (11%) subjects developed new CWP. Although subjects with a low baseline pain threshold were not at increased risk of developing symptoms, a high tender point count, adjusted for age, sex, baseline pain status and other confounding factors, predicted the development of new CWP.

CONCLUSION

Subjects free of CWP are at an increased risk of its development if they have a high tender point count. However, a low-pressure pain threshold does not predict the onset of symptoms. Data from this population-based prospective study suggest that a low pain threshold in subjects with CWP is likely to be a secondary phenomenon as a result of pain or associated distress rather than the antecedent of symptoms.

Predicting the onset of knee pain: results from a 2-year prospective study of new workers

OBJECTIVE

To determine the relative contribution of work-related mechanical (injury) factors and psychosocial factors to the onset of a new episode of knee pain, in a cohort of newly employed workers.

METHODS

A prospective cohort study of newly employed workers from 12 diverse occupational settings in England (The New Workers Study). 859 newly employed workers, free of knee pain, were identified. Information about occupational mechanical factors (manual handling and postural activities), the occupational physical environment, and psychological and psychosocial factors was collected by self-completion questionnaires. Participants were followed up after 12 and 24 months to identify cases of knee pain onset. Generalised estimating equations were used to estimate the risk of new-onset knee pain, with respect to the exposures previously measured.

RESULTS

In total, over the 2-year follow-up period, 108 cases of new-onset knee pain were observed. Mechanical load, postural factors, psychological distress and work-place psychosocial factors all influenced the risk of new-onset knee pain over the 2-year follow-up period. On multivariate analysis, two factors remained independently predictive of knee pain onset: lifting or carrying heavy weights in one hand, and the level of general psychological distress.

CONCLUSION

In addition to mechanical (injury) factors, psychological factors are important risk factors for knee pain onset as shown in a population of young newly employed workers.

Moderation of psychosocial risk factors through dysfunction of the hypothalamic–pituitary–adrenal stress axis in the onset of chronic widespread musculoskeletal pain : Findings of a population-based prospective cohort study

OBJECTIVE

To test the hypothesis that abnormalities in the hypothalamic-pituitary-adrenal (HPA) stress-response system would act as an effect moderator between HPA function and the onset of chronic widespread pain (CWP).

METHODS

We conducted a population-based prospective cohort study. Current pain and psychosocial status were ascertained in 11,000 subjects. Of the 768 eligible subjects free of CWP but at future risk based on their psychosocial profile, 463 were randomly selected, and 267 (57.7%) consented to assessment of their HPA axis function. Diurnal function was measured by assessing levels of salivary cortisol in the morning (9:00 AM) and evening (10:00 PM). Serum cortisol levels were measured after an overnight low-dose (0.25 mg) dexamethasone suppression test and a potentially stressful clinical examination. All subjects were followed up 15 months later to identify cases of new-onset CWP.

RESULTS

A total of 241 subjects (94.9%) completed the followup study, and 28 (11.6%) reported the new onset of CWP. High levels of cortisol post-dexamethasone (odds ratio [OR] 3.53, 95% confidence interval [95% CI] 1.17-10.65), low levels in morning saliva (OR 1.43, 95% CI 0.52-3.94), and high levels in evening saliva (OR 2.32, 95% CI 0.64-8.42) were all associated with CWP. These 3 factors were found to be independent and additive predictors of CWP (OR for all 3 factors 8.5, 95% CI 1.5-47.9) in analyses controlling for age, sex, depression, sleep disturbance, recent traumatic life events, and pain status. One or more of these 3 HPA factors identified 26 (92.9%) cases of new-onset CWP.

CONCLUSION

Among a group of psychologically at-risk subjects, dysfunction of the HPA axis helps to distinguish those who will and will not develop new-onset CWP.

The epidemiology of chronic syndromes that are frequently unexplained: do they have common associated factors?

BACKGROUND

Syndromes for which no physical or pathological changes can be found tend to be researched and managed in isolation although hypotheses suggest that they may be one entity. The objectives of our study were to investigate the co-occurrence, in the general population, of syndromes that are frequently unexplained and to evaluate whether they have common associated factors.

METHODS

We conducted a population-based cross-sectional survey that included 2,299 subjects who were registered with a General Medical Practice in North-west England and who completed full postal questionnaires (response rate 72%). The study investigated four chronic syndromes that are frequently unexplained: chronic widespread pain, chronic oro-facial pain, irritable bowel syndrome, and chronic fatigue. Validated instruments were used to measure the occurrence of syndromes and to collect information on a variety of associated factors: demographic (age, gender), psychosocial (anxiety, depression, illness behaviour), life stressors, and reporting of somatic symptoms.

RESULTS

We found that 587 subjects (27%) reported one or more syndromes: 404 (18%) reported one, 134 (6%) reported two, 34 (2%) reported three, and 15 (1%) reported all four syndromes. The occurrence of multiple syndromes was greater than would be expected by chance (P < 0.001). There were factors that were common across syndromes: female gender [odds ratio (OR) = 1.8; 95% confidence interval (95% CI) 1.5-2.2], high levels of aspects of health anxiety like health worry preoccupation (OR = 3.5; 95% CI 2.8-4.4) and reassurance seeking behaviour (OR = 1.4; 95% CI 1.1-1.7), reporting of other somatic symptoms (OR = 3.6; 95% CI 2.9-4.4), and reporting of recent adverse life events (OR = 2.3; 95% CI 1.9-2.8).

CONCLUSION

This study has shown that chronic syndromes that are frequently unexplained co-occur in the general population and share common associated factors. Primary care practitioners need to be aware of these characteristics so that management is appropriate at the outset.

Hypothalamic-pituitary-adrenal stress axis function and the relationship with chronic widespread pain and its antecedents

In clinic studies, altered hypothalamic-pituitary-adrenal (HPA) axis function has been associated with fibromyalgia, a syndrome characterised by chronic widespread body pain. These results may be explained by the associated high rates of psychological distress and somatisation. We address the hypothesis that the latter, rather than the pain, might explain the HPA results. A population study ascertained pain and psychological status in subjects aged 25 to 65 years. Random samples were selected from the following three groups: satisfying criteria for chronic widespread pain; free of chronic widespread pain but with strong evidence of somatisation ('at risk'); and a reference group. HPA axis function was assessed from measuring early morning and evening salivary cortisol levels, and serum cortisol after physical (pain pressure threshold exam) and chemical (overnight 0.25 mg dexamethasone suppression test) stressors. The relationship between HPA function with pain and the various psychosocial scales assessed was modelled using appropriate regression analyses, adjusted for age and gender. In all 131 persons with chronic widespread pain (participation rate 74%), 267 'at risk' (58%) and 56 controls (70%) were studied. Those in the chronic widespread pain and 'at risk' groups were, respectively, 3.1 (95% CI (1.3, 7.3)) and 1.8 (0.8, 4.0) times more likely to have a saliva cortisol score in the lowest third. None of the psychosocial factors measured were, however, associated with saliva cortisol scores. Further, those in the chronic widespread pain (1.9 (0.8, 4.7)) and 'at risk' (1.6 (0.7, 3.6)) groups were also more likely to have the highest serum cortisol scores. High post-stress serum cortisol was related to high levels of psychological distress (p = 0.05, 95% CI (0.02, 0.08)). After adjusting for levels of psychological distress, the association between chronic widespread pain and post-stress cortisol scores remained, albeit slightly attenuated. This is the first population study to demonstrate that those with established, and those psychologically at risk of, chronic widespread pain demonstrate abnormalities of HPA axis function, which are more marked in the former group. Although some aspects of the altered function are related to the psychosocial factors measured, we conclude that the occurrence of HPA abnormality in persons with chronic widespread pain is not fully explained by the accompanying psychological stress.

Poor sleep and depression are independently associated with a reduced pain threshold. Results of a population based study

To determine the relative contributions of psychological factors and sleep disturbance to reduced pain threshold we conducted a cross-sectional two-phase population-based study. A total of 424 subjects were recruited, stratified by pain and distress status. Subjects completed a postal questionnaire that asked about current pain and covered aspects of psychological status and sleep disturbance. Samples of subjects stratified by the extent of bodily pain they reported and psychological status were invited to participate in an examination of pain threshold. The association between psychological status, sleep disturbance and a low pain threshold was examined using ordinal regression. High levels of psychological distress (OR=1.6, 95% CI (1.02, 2.5)), disturbed sleep (OR=2.2, 95% CI (1.4, 3.5)) and high scores on the HAD depression scale (OR=2.1, 95% CI (1.3, 3.2)) were all associated with having a low pain threshold. In multivariate analysis disturbed sleep and depression remained independently associated with a low pain threshold. These relationships persisted after adjustment for pain status. This study had demonstrated that depression and poor sleep are associated with a reduced pain threshold.

Is musculoskeletal pain more common now than 40 years ago?: two population-based cross-sectional studies

OBJECTIVE

To test the hypothesis that the prevalence of specific musculoskeletal pain symptoms has increased over time in the northwest region of England. To meet this objective we have examined the difference in the prevalence of low back, shoulder and widespread pain between the 1950s and today using historical data collected by the Arthritis Research Campaign (arc).

METHODS

Two cross-sectional surveys conducted over 40 yr apart in the northwest region of England. The status of two regional pain sites and widespread pain was determined using interview and questionnaire responses, for the earlier and later studies respectively. Subjects were classified positively if they reported low back pain, shoulder pain or widespread pain on the day of the survey. Rates were standardized to the Greater Manchester population.

RESULTS

There were large differences in the prevalence of musculoskeletal pain between the two surveys. For all three symptoms examined prevalence increased from 2- to 4-fold between the two surveys. In both surveys low back pain was more common in women. Shoulder and widespread pain was less prevalent in women than in men in the earlier survey but by the time of the later survey women reported more pain at these sites.

CONCLUSIONS

The prevalence of musculoskeletal pain is much higher than that reported over 40 yr ago. The change in prevalence is unlikely to be entirely due to the study design; other possible explanations such as the increased reporting or awareness of these symptoms is discussed.

Primary care consultation predictors in men and women: a cohort study

BACKGROUND

Women visit their doctors more than men, but comparatively few studies have explored gender differences in consultation in detail.

AIMS

To identify the factors that predicted the number of primary care consultations in men and women over a 5-year period.

DESIGN OF STUDY

Prospective cohort study with three waves of data collection by postal questionnaire.

SETTING

A single suburban general practice in Greater Manchester, UK.

METHOD

Consultation data were sought from primary care records on a random sample of 800 adults. The main outcome measure was the number of consultations over the 5 years of the study. Questionnaire measures included the 12-item version of the General Health Questionnaire, the Illness Attitude Scales, a somatic symptom scale, a fatigue scale, and a functional assessment of disability.

RESULTS

Consultation data were obtained on 738 patients (445 women, 293 men, 92% of selected subjects). Longitudinal models of consultation over 5 years showed that changes in psychological distress were more strongly associated with consultation in women than in men, whereas cognitive factors (negative illness attitudes) were more strongly associated with the consultation rate in men than women.

CONCLUSION

The predictors of consultation in primary care may be different for men and women. A fuller understanding of the reasons for consultation may enable primary care doctors to better help individual patients, as well as perhaps contributing more generally to the development of gender specific interventions for those who consult unusually frequently.

Psychological distress and premature mortality in the general population: a prospective study

PURPOSE

To determine whether higher rates of mortality are observed in people reporting psychological distress, to establish the nature of any excess, and to examine the possible existence of a dose response relationship.

METHODS

We conducted a prospective follow-up study of mortality over an eight-year period in the North West of England. A total of 4,501 adults were recruited from two general practices during a population-based survey conducted at the start of 1992. At baseline psychological distress was assessed using the General Health Questionnaire (12-item version, GHQ-12). The relationship between levels of distress and subsequent mortality was examined using Cox proportional hazard models.

RESULTS

Risk of all-cause mortality was greatest in subjects reporting the highest levels of distress (hazard ratio (HR) 1.71, 95% CI 1.32-2.23) but was also raised in subjects reporting intermediate distress (HR 1.38 95% CI 1.06-1.79) when compared to those reporting no distress. Increased risk of mortality in subjects reporting distress appeared to be due largely to an excess of deaths from ischaemic heart disease (high distress, HR 1.90, 95% CI 1.08-3.35; intermediate distress, HR 1.58, 95% CI 0.90-2.76) and respiratory diseases (high distress, HR 5.39, 95% CI 2.70-10.78; intermediate distress, HR 2.33, 95% CI 1.12-4.22).

CONCLUSIONS

The association between mortality and psychological distress observed in this study seems to arise largely because of premature deaths from ischaemic heart disease and respiratory diseases. The existence of a dose-response effect between distress and mortality provides further evidence to support the existence of a casual relationship.

Childhood experience and health care use in adulthood: nested case--control study

BACKGROUND

Few studies have considered the role of childhood experiences in adult health care use.

AIMS

To examine the hypotheses that individuals frequently attending primary care report childhood adversities and illness exposures more commonly than the remainder of patients and that any association is independent of adult psychiatric disorder.

METHOD

A nested case-control study was carried out in a single general practice in Manchester, UK. Fifty frequent attenders (randomly selected from adult patients in the top decile of consultation frequency) and fifty normal attenders (randomly selected from the remainder of adult patients) underwent a structured psychiatric interview and a detailed, semi-structured interview of childhood experience.

RESULTS

There was a strong association between frequent attendance and childhood experiences. Multivariate analysis suggested that reported childhood illness exposures and reports of childhood adversity were each associated independently with adult consultation behaviour, even after adjustment for adult psychiatric disorder.

CONCLUSIONS

Interventions for high users of health care may need to address childhood experiences of illness and childhood adversities, as well as adult psychiatric disorder.

Psychosocial and illness related predictors of consultation rates in primary care--a cohort study

BACKGROUND

Despite extensive research, the reasons why patients consult their doctors are unclear. The aim of the current study was to identify the psychosocial and illness related factors that independently predicted primary care consultation over a 5-year period.

METHOD

We carried out a prospective, population-based cohort study with three waves of data collection by postal questionnaire in one general practice in Greater Manchester (UK). Consultation data were sought from primary care records on a random subsample of 800 adult patients. The main outcome measure was the number of consultations (including surgery and home visits) over the 5 years of the study as determined by raters blind to questionnaire responses. Questionnaire measures included the 12-item version of the General Health Questionnaire, the Illness Attitude Scales, a somatic symptom scale, a fatigue scale, a functional assessment of disability.

RESULTS

Consultation data were obtained on 738 patients (92% of selected subjects), who accounted for 12182 consultations. Negative illness attitudes, the presence of physical and psychiatric disorder, health anxiety, changes in psychological distress, reported physical symptoms and demographic factors such as age and sex were independently associated with consultation over a 5-year period. These variables together accounted for a difference of ten consultations per year between groups.

CONCLUSION

Consultation in primary care is a complex behaviour with a complex aetiology. Terms such as 'frequent attenders' may be less helpful than recognizing a number of dimensions that operate across the whole spectrum of consultation frequency. Future research should consider the wider context of consultation.

Mechanical injury and psychosocial factors in the work place predict the onset of widespread body pain: A two-year prospective study among cohorts of newly employed workers

OBJECTIVE

Mechanical injury has been postulated as a risk factor for widespread pain, although to date, the evidence is weak. The aim of this study was to determine whether repeated exposure to mechanical trauma in the work place predicts the onset of widespread pain and to determine the relative contribution of mechanical trauma compared with psychosocial factors.

METHODS

In this prospective cohort study of 1,081 newly employed subjects in 12 diverse occupational settings, we collected detailed information on mechanical exposure, posture, physical environment, and psychosocial risk factors in the work place. Study questionnaires were completed at baseline and at 12 and 24 months. Individuals free of widespread pain at baseline and 12 months were eligible for followup. Generalized estimating equations were used to determine which factors predicted the new onset of widespread pain.

RESULTS

Of the 1,081 baseline respondents, 896 were free of widespread pain and were eligible for further study. Of these 896 subjects, 708 and 520 responded at 12 months and 24 months, respectively. The rates of new-onset widespread pain were 15% at 12 months and 12% at 24 months. Several work place mechanical and posture exposures predicted the new onset of widespread pain: lifting >15 lbs with 1 hand, lifting >24 lbs with 2 hands, pulling >56 lbs, prolonged squatting, and prolonged working with hands at or above shoulder level. Of the psychosocial exposures, those who reported low job satisfaction, low social support, and monotonous work had an increased risk of new-onset widespread pain. In multivariate analysis, monotonous work and low social support were found to be the strongest independent predictors of symptom onset.

CONCLUSION

Our findings demonstrate that the prevalence of new-onset widespread pain was high, but among this young, newly employed work force, both physical and psychosocial factors played an important role.

[The prevalence of chronic generalized pain and its relationship to demographic characteristics and mental status]

Chronic generalized pain (CGP) as one of the diagnostic criteria of fibromyalgia is a common condition amongst the populations of Western Europe and the USA. The prevalence of CGP in these countries is 10.7-13.2%. The etiology of CGP is unclear; however, several findings suggest that this is a process of somatization that masks affective disorders. There have been no studies of the epidemiology of CGP in Russia. The study was undertaken to determine the prevalence of CGP in the Yekaterinburg adult population and to examine the relationship of CGP to its demographic characteristics and affective disorders. A ostal cross-sectional population survey was conducted. This covered 159 persons (54 males and 105 females) aged 27 to 75 years who had been randomly selected from the election lists of Yekaterinburg residents. A questionnaire was posted to each participant in order to reveal whether a respondent had experienced pain a month before, to define its location, duration, severity, and to evaluate psychoemotional disorders. The response rate was 75.5% (120 replies). The prevalence of CGP was 13.3%. There was no relationship of the sex of a respondent to CGP. The latter was shown to be associated with age. There was also its significant association with psychoemotional disorders. CGP is a common condition in the Yekateringburg population, which occurs in every 8 adult residents, more frequently in those aged above 43 years. The individuals who suffer from CGP exhibit a high level of psychological distress.

The role of workplace low-level mechanical trauma, posture and environment in the onset of chronic widespread pain

BACKGROUND

We have recently demonstrated that individual psychosocial factors are important predictors of the onset of chronic widespread pain. It has been hypothesized that excessive mechanical exposure may also be associated with symptom onset, although this has not been formally examined. We therefore determined the relative contributions of individual psychosocial and work-related mechanical, posture and environment factors in symptom onset.

METHODS

We conducted a population-based prospective survey and identified 1658 adults aged 18-65 yr who were symptom-free. At baseline, detailed information was obtained on work-related mechanical and environment factors using validated instruments. Individual psychosocial features were also measured. Subjects free of chronic widespread pain at baseline were followed up at 12 and 36 months to identify those reporting the onset of new symptoms.

RESULTS

In all, 1445 (91%) returned the questionnaire at 12 months and 978 (89%) at 36 months. Of these, 81 and 92 respectively reported new chronic widespread pain. Symptom onset was predicted by workplace factors [pushing/pulling heavy weights [relative risk (RR) = 1.8, 95% confidence interval (CI) 1.1, 3.0]; repetitive movements of the wrists (RR = 1.8, 95% CI 1.2, 2.7); kneeling (RR = 2.2, 95% CI 1.2, 4.1)] and individual factors [aspects of illness behaviour (RR = 2.9, 95% CI 1.6, 5.3); somatic symptoms (RR = 1.9 95% CI 1.1, 3.3); fatigue (RR = 1.9, 95% CI 1.2, 3.1); baseline pain symptoms (RR = 2.5, 95% CI 1.6, 3.9)]. In multivariate analysis, pushing/pulling heavy weights, repetitive wrist movements, kneeling and other pain at baseline were associated with new-onset chronic widespread pain. However, the strongest predictor was a high score on the illness behaviour scale.

CONCLUSION

This study provides only limited support for the hypothesis that low-level mechanical injury may be a risk factor for developing chronic widespread pain. The onset of chronic widespread pain appears to be multifactorial and is strongly predicted by individual psychosocial factors.

Mechanical and psychosocial factors predict new onset shoulder pain: a prospective cohort study of newly employed workers

AIM

To test the hypothesis that work related mechanical and psychosocial factors predict new onset shoulder pain in newly employed workers.

METHODS

Two year prospective study of newly employed workers from 12 diverse occupational settings. At baseline, 1081 subjects provided information on work related mechanical and psychosocial risk factors, and current pain status.

RESULTS

In all, 803 (74%) subjects were free from shoulder pain at baseline. Of those, 638 (79%) responded at 12 months and 476 (88%) at 24 months. New onset shoulder pain was reported by 93 (15%) and 73 (15%) subjects respectively. An increased risk of symptom onset was found in subjects reporting mechanical exposures involving heavy weights including lifting with one or two hands, carrying on one shoulder, lifting at or above shoulder level, and pushing or pulling. Working with hands above shoulder level was also predictive of new onset shoulder pain. Of the psychosocial factors examined, the strongest predictor was monotonous work. Those individuals with any other previous pain also had an increased risk of new onset shoulder pain at follow up. In multivariate analysis, lifting heavy weights with one or two hands, pushing or pulling heavy weights, working with hands above shoulder level, and monotonous work were independently associated with new onset shoulder pain.

CONCLUSIONS

This study supports the hypothesised relation between mechanical risk factors and shoulder pain. In general, work related psychosocial factors were modestly associated with new onset shoulder pain. However, monotonous work was a strong risk factor for new onset shoulder pain.

Risk factors for new-onset low back pain amongst cohorts of newly employed workers

OBJECTIVES

To test the hypothesis that work-related mechanical, psychosocial and physical environment factors would predict new-onset low back pain (LBP) in newly employed workers.

METHODS

A total of 1186 newly employed workers were recruited from a variety of occupational settings. Those who were free from LBP at baseline were identified. Subjects were followed up at 12 and 24 months. Work-related mechanical, psychosocial and physical environment exposures were measured. Generalized estimating equations were used to assess predictors of new-onset LBP.

RESULTS

New-onset LBP was reported by 119 (19%) and 81 (19%) subjects at 12 and 24 months, respectively. Several work-related mechanical exposures predicted new-onset LBP including lifting heavy weights with one or two hands, lifting heavy weights at or above shoulder level, pulling heavy weights, kneeling or squatting for 15 min or longer. Of the psychosocial factors examined, stressful and monotonous work significantly predicted symptom onset. In addition, hot working conditions and pain at other sites also predicted new-onset LBP. On multivariate analysis these risks were only moderately attenuated but the 95% confidence intervals excluded unity only for the latter, non-mechanical, exposures.

CONCLUSION

In this cohort of newly employed workers, from a range of occupations, several aspects of the work-place environment, other than mechanical factors, were important in predicting new-onset LBP. These results emphasize that interventions aimed at reducing the occurrence of LBP are likely to be most successful if they intervene across these domains.

Association of widespread body pain with an increased risk of cancer and reduced cancer survival: a prospective, population-based study

OBJECTIVE

To determine whether reported widespread body pain is related to an increased incidence of cancer and/or reduced survival from cancer, since our previous population surveys have demonstrated a relationship between widespread body pain and a subsequent 2-fold increase in mortality from cancer over an 8-year period.

METHODS

A total of 6565 subjects in Northwest England participated in 2 health surveys during 1991-1992. The subjects were classified according to their reported pain status (no pain, regional pain, and widespread pain), and were subsequently followed up prospectively until December 31, 1999. During followup, information was collected on incidence of cancer and survival rates among those developing cancer. Associations between the original pain status and development of cancer and cancer survival were expressed as the incidence rate ratio (IRR) and mortality rate ratio (MRR), respectively. All analyses were adjusted for age, sex, and study location, the latter being a proxy measure of socioeconomic status.

RESULTS

Among the study population, 6331 had never been diagnosed with cancer at the time of participation in the survey. Of these subjects, 956 (15%) were classified as having widespread pain, 3061 (48%) as having regional pain, and 2314 (37%) as having no pain. There were a total of 395 first malignancies recorded during followup. In comparison with subjects reporting no pain, those with regional pain (IRR 1.19, 95% confidence interval [95% CI] 0.94-1.50) and widespread pain (IRR 1.61, 95% CI 1.21-2.13) experienced an excess incidence of cancer during the followup period. The increased incidence among subjects previously reporting widespread pain was related, most strongly, to breast cancer (IRR 3.67, 95% CI 1.39-9.68), but there were also cancers of the prostate (IRR 3.46, 95% CI 1.25-9.59), large bowel (IRR 2.35, 95% CI 0.96-5.77), and lung (IRR 2.04, 95% CI 0.96-4.34). Subjects reporting widespread pain who subsequently developed cancer, in comparison with those previously reporting no pain, had an increased risk of death (MRR 1.82, 95% CI 1.18-2.80). This decreased survival was highest among subjects with cancers of the breast and prostate, although the effects on site-specific survival were nonsignificant.

CONCLUSION

This study has demonstrated that widespread pain reported in population surveys is associated with a substantial subsequent increased incidence of cancer and reduced cancer survival. At present there are no satisfactory biologic explanations for this observation, although several possible leads have been identified.

Psychosocial risk factors for the onset of abdominal pain. Results from a large prospective population-based study

OBJECTIVE

To determine the psychosocial risk factors for the development of abdominal pain and to determine whether, in those people who consulted, symptoms had been attributed to an organic cause.

DESIGN

Prospective population-based postal survey with follow-up survey at 12 months.

SETTING

A mixed sociodemographic suburban area of Manchester, UK.

PARTICIPANTS

Subjects aged 18-65 years were randomly selected from a population-based primary care register who had responded to a detailed pain questionnaire, which included a pain manikin drawing. They also completed the following psychosocial instruments: General Health Questionnaire, Somatic Symptom Checklist, Fatigue Questionnaire and the Illness Attitude Scales (including the 'health anxiety' and 'illness behaviour' sub-scales).

MAIN OUTCOME MEASURES

The onset of new abdominal pain.

RESULTS

Of the 1953 participants at baseline, 1763 were free of abdominal pain: 1551 were followed up at 12 months (adjusted follow-up rate of 92%) of which 69 subjects reported new abdominal pain (new onset rate 4.6%). New abdominal pain was similar in females (4.9%) and males (4.2%), and did not vary by age group. Baseline factors which predicted onset were high levels of fatigue (odds ratio [OR] = 3.3, 95% CI: 1.9-5.8), psychological distress (OR = 3.4, 95% CI: 1.9-6.0), high scores on the illness behaviour scale (OR = 3.3, 95% CI: 1.7-6.7) and high levels of health anxiety (OR = 2.1, 95% CI: 1.1-3.9). Reporting low back pain at baseline was also associated with an increased risk of reporting abdominal pain (OR = 2.0, 95% CI: 1.2-3.3). On multivariate analysis, high levels of psychological distress and aspects of prior illness behaviour were the major independent predictors of outcome. Of those who sought health care, only one consultation led to a definite diagnosis.

CONCLUSION

In subjects free of abdominal pain, psychological distress, fatigue, health anxiety and illness behaviour are predictors of future onset rather than merely a consequence of symptoms. These results suggest that abdominal pain shares some common features of onset with pain at other sites thought not to be primarily organic in origin.

Does chronic pain predict future psychological distress?

Cross-sectional studies have consistently shown a relationship between chronic widespread pain, the clinical hallmark of fibromyalgia, and psychological distress. These studies cannot distinguish the direction of any causal relationship. Recent population based studies have reported that such pain is predictive of future distress. However, chronic pain is often associated with physical and psychological co-morbid features which may confound this relationship. The aim of this study was to examine the hypothesis that chronic widespread pain increases the risk of future distress after adjusting for the effects of possible confounding factors. A population based survey of 1953 individuals identified subjects' psychological status and whether they satisfied criteria for chronic widespread pain. At baseline co-morbid features of chronic widespread pain, including reporting other somatic symptoms, abnormal illness behaviour, health anxiety, fatigue and low levels of self-care, were measured. All subjects were followed up after 12 months to determine levels of psychological distress. Subjects with chronic widespread pain at baseline were much more likely to be distressed at follow up (OR=4.0, 95% CI (2.5,6.3)). As levels of distress at follow up may simply reflect those at baseline the association was adjusted for baseline levels of distress. Chronic widespread pain was, however, still associated with future distress although the relationship was slightly attenuated (odds ratio, OR=3.0, 95% CI (1.8,5.1)). To examine our main hypothesis a final analysis was undertaken adjusting this association for those co-morbid features assessed at baseline. Following these adjustments chronic widespread pain was no longer significantly associated with future distress (OR=1.5, 95% CI (0.8,2.9)). Chronic widespread pain was associated with increased levels of psychological distress at follow up. However, a more rigorous analysis indicated that the association between baseline pain status with future distress was explained by concomitant features of chronic pain rather than pain per se. These findings indicate that it is those persons with chronic widespread pain in the presence of other physical and psychosocial factors who will become distressed.

Associations between adverse events in childhood and chronic widespread pain in adulthood: are they explained by differential recall?

OBJECTIVE

Clinic based studies suggest that adverse events in childhood may predispose to chronic pain in adult life. These have been conducted on highly selected groups, and it is unknown whether these relationships hold in the general population and to what extent the increased rate of adverse childhood events in persons with pain is an artefact of differential reporting. We examined the hypothesis that chronic widespread pain was associated with reports of adverse experiences in childhood and whether any observed relationships could be explained by differential recall.

METHODS

A cross sectional population based screening survey was conducted. Subjects completed a questionnaire that included assessments of pain and psychological state. In total, 296 subjects who had demonstrated psychological distress were randomly selected and had a detailed interview, which included an assessment of 14 adverse childhood experiences. Medical records relating to childhood were also examined for those subjects.

RESULTS

The prevalence of self-reported adverse childhood experiences was greatest in adult subjects with current chronic widespread pain. Exposure to illness in family members, parental loss, operations, and abuse were all associated with increased, but nonsignificant, odds of having chronic widespread pain versus those without such exposures. However the only statistically significant association was with childhood hospitalizations. From medical record information the associations of hospitalizations (OR 5.1, 95% CI 2.0-13.0) and operations (OR 3.0, 95% CI 1.2-7.2) with pain previously noted were partly explained by differential recall between subjects with and without pain: hospitalizations, OR 2.2, 95% CI 0.9-5.5; operations, OR 1.2, 95% CI 0.5-3.4.

CONCLUSION

Although several reported adverse events in childhood were observed to be associated with chronic widespread pain in adulthood, only reports of hospitalizations were significantly associated. Validation of self-reported exposures suggests that there was differential recall of past events among those with and without pain, and this differential recall explained the association between hospitalizations and current chronic pain. Such differential recall may explain other observations of an association between reports of adverse childhood events and chronic pain in adulthood.

Widespread body pain and mortality: prospective population based study

OBJECTIVE

To determine whether there is excess mortality in groups of people who report widespread body pain, and if so to establish the nature and extent of any excess.

DESIGN

Prospective follow up study over eight years. Mortality rate ratios were adjusted for age group, sex, and study location.

SETTING

North west England.

PARTICIPANTS

6569 people who took part in two pain surveys during 1991-2.

MAIN OUTCOME MEASURES

Pain status at baseline and subsequent mortality.

RESULTS

1005 (15%) participants had widespread pain, 3176 (48%) had regional pain, and 2388 (36%) had no pain. During follow up mortality was higher in people with regional pain (mortality rate ratio 1.21, 95% confidence interval 1.01 to 1.44) and widespread pain (1.31, 1.05 to 1.65) than in those who reported no pain. The excess mortality among people with regional and widespread pain was almost entirely related to deaths from cancer (1.55 (1.09 to 2.19) for regional pain and 2.07 (1.37 to 3.13) for widespread pain). The excess cancer mortality remained after exclusion of people in whom cancer had been diagnosed before the original survey and after adjustment for potential confounding factors. There were also more deaths from causes other than disease (for example, accidents, suicide, violence) among people with widespread pain (5.21, 0.94 to 28.78).

CONCLUSION

There is an intriguing association between the report of widespread pain and subsequent death from cancer in the medium and long term. This may have implications for the long term follow up of patients with "unexplained" widespread pain symptoms, such as those with fibromyalgia.

The role of psychiatric disorders in fibromyalgia

The cardinal features of fibromyalgia are chronic widespread pain in the presence of widespread tenderness as measured by multiple tender points. Despite extensive investigations, the etiology of this syndrome remains unclear. Increased rates of psychiatric disorders, particularly depressive, anxiety, and somatoform disorders, are apparent in clinic populations. Epidemiologic evidence suggests that this is also true for community subjects. Depression, generalized psychological distress, and other psychological factors have been shown to be associated with the onset and persistence of fibromyalgia symptoms. However, the bodily processes through which such factors may lead to the onset of fibromyalgia are unclear. Recent investigations have demonstrated altered stress system responsiveness, most notably the hypothalamic-pituitary-adrenal stress axis, in patients with fibromyalgia. These findings, and one promising avenue for investigating the interaction between psychological and biological factors in the onset of chronic pain syndromes including fibromyalgia, are discussed.

Features of somatization predict the onset of chronic widespread pain: results of a large population-based study

OBJECTIVE

Chronic widespread pain, the clinical hallmark of the fibromyalgia syndrome, is associated with other physical and psychological symptoms both in patients studied in a clinical setting and in those identified in the community. The present study was undertaken to examine the hypothesis that psychological and physical indicators of the process of somatization predict the development of new chronic widespread pain.

METHODS

In this population-based prospective study, 1,658 adults ages 18-65 years completed a detailed pain questionnaire, which included a pain drawing. They also completed the following psychosocial instruments: General Health Questionnaire, Somatic Symptom Checklist, Fatigue Questionnaire, and Illness Attitude Scales. Individuals were followed up at 12 months, at which time 1,480 (93% of subjects still living at their baseline address) provided data on pain status, using the same instruments.

RESULTS

At baseline, 825 subjects were classified as pain free and 833 as having pain not satisfying criteria for chronic widespread pain. Of those, 18 (2%) and 63 (8%), respectively, were classified as having chronic widespread pain at followup. After adjustment for age and sex, there were strong relationships between baseline test scores and subsequent risk of chronic widespread pain (odds ratio for the Somatic Symptom Checklist 3.3; odds ratio for the Illness Behavior subscale of the Illness Attitude Scales 9.0). All 95% confidence intervals excluded unity. These associations were independent of baseline pain status.

CONCLUSION

Subjects who are free of chronic widespread pain are at increased future risk of its development if they display other aspects of the process of somatization. Data from this population-based prospective study lend powerful support to the hypothesis that chronic widespread pain can be one manifestation of the somatization of distress.

Risk factors for persistent chronic widespread pain: a community-based study

BACKGROUND

Chronic widespread pain is the cardinal clinical feature of the fibromyalgia syndrome, which, in the majority of clinic patients, is persistent. By contrast, in community-derived patients, pain is persistent in only half of the affected individuals, particularly those with psychological distress. Whether such distress is a consequence of the pain or a manifestation of a wider process of somatization which is associated with the persistence of pain is unclear.

OBJECTIVES

We tested in a large, prospective, population-based study the hypothesis that features of somatization predict the persistence of chronic widespread pain.

METHODS

In all, 252 (13%) of 1953 adult subjects selected from a population register were classified as having chronic widespread pain based on a detailed questionnaire which included a pain drawing. The patients also completed a number of psychosocial instruments which measure features known to be associated with somatization. Two hundred and twenty-five (91%) of the patients were successfully followed up after 12 months and provided data on pain status using the same instruments.

RESULTS

In all, 126 (56%) patients reported chronic widespread pain at follow-up, 74 (33%) reported other pain and 25 (11%) reported no pain. Persistent chronic widespread pain was strongly associated with baseline test scores for high psychological distress and fatigue. In addition, these subjects were more likely to display a pattern of illness behaviour characterized by frequent visits to medical practitioners for symptoms which disrupt daily activities. The prevalence of persistent pain increased with the number of risk factors the subjects were exposed to.

CONCLUSIONS

Although almost half of the cases of chronic widespread pain resolved within 1 yr, this study has demonstrated for the first time that those subjects who display features of somatization are more likely to have widespread pain which persists. These findings have implications for the identification and treatment of persons with persistent chronic widespread pain.

The association between chronic widespread pain and mental disorder: a population-based study

OBJECTIVE

Patients with chronic widespread pain (CWP) have been reported to have a greater prevalence of mental disorders and somatization than that found in the general population, but the true association between CWP and mental disorders is unknown. In this study, we investigated whether there is an increased prevalence of mental disorder in people with CWP from the general population. We also describe the psychiatric diagnoses associated with CWP.

METHODS

In a population-based case-control study, 1,953 subjects (75% of a random sample of individuals age 18-65 years) completed a questionnaire that included a pain assessment and the 12-item General Health Questionnaire (GHQ-12). Of 710 subjects scoring >1 on the GHQ-12, 301 were assessed further using a structured psychiatric interview and detailed assessment of medical records to identify cases of mental disorder, in accordance with criteria of the 10th edition of the International Classification of Diseases. The association between CWP and mental disorder was modeled using logistic regression, adjusting for possible confounders including age, sex, and nonresponders.

RESULTS

We estimated the overall population prevalence of mental illness to be 11.9%. The odds of having a mental disorder for subjects with versus those without CWP were 3.18 (95% confidence interval 1.97-5.11). Most subjects with mental disorders were diagnosed as having mood and anxiety disorders. Only 3 cases of somatoform disorders were identified, and all were associated with pain.

CONCLUSION

This study, although unable to demonstrate a cause-and-effect relationship, showed that 16.9% of those with CWP were estimated to have a psychiatric diagnosis, suggesting that these disorders should be identified and treated.