The feasibility and acceptability of a physical activity intervention for older people with chronic musculoskeletal pain: The iPOPP pilot trial protocol.

INTRODUCTION: This pilot trial will inform the design and methods of a future full-scale randomized controlled trial (RCT) and examine the feasibility, acceptability and fidelity of the Increasing Physical activity in Older People with chronic Pain (iPOPP) intervention, a healthcare assistant (HCA)-supported intervention to promote walking in older adults with chronic musculoskeletal pain in a primary care setting. METHODS AND ANALYSIS: The iPOPP study is an individually randomized, multicentre, three-parallel-arm pilot RCT. A total of 150 participants aged ≥65 years with chronic pain in one or more index sites will be recruited and randomized using random permuted blocks, stratified by general practice, to: (i) usual care plus written information; (ii) pedometer plus usual care and written information; or (iii) the iPOPP intervention. A theoretically informed mixed-methods approach will be employed using semi-structured interviews, audio recordings of the HCA consultations, self-reported questionnaires, case report forms and objective physical activity data collection (accelerometry). Follow-up will be conducted 12 weeks post-randomization. Collection of the quantitative data and statistical analysis will be performed blinded to treatment allocation, and analysis will be exploratory to inform the design and methods of a future RCT. Analysis of the HCA consultation recordings will focus on the use of a checklist to determine the fidelity of the iPOPP intervention delivery, and the interview data will be analysed using a constant comparison approach in order to generate conceptual themes focused around the acceptability and feasibility of the trial, and then mapped to the Theoretical Domains Framework to understand barriers and facilitators to behaviour change. A triangulation protocol will be used to integrate quantitative and qualitative data and findings.

Using Smartphones for Research Outside Clinical Settings: How Operating Systems, App Developers, and Users Determine Geolocation Data Quality in mHealth Studies.

Smartphones that collect user geolocation provid opportunities for mobile Health (mHealth). Although granularity of geolocation data may be high, data completeness depends on the device's operating system, application developer decisions, and user actions. We investigate completeness of geolocation data collected via smartphones of 5601 people that self-reported daily chronic pain symptoms on 349,293 days. On 17% of these days, hourly geolocation data is reported, but days with 0 (16%), 1 (14%) and 2 (13%) geolocations are common. Android phones collect geolocation more often than iPhones (median 17 versus 2 times a day). Factors on operating system level and individual user level influence completeness of geolocation data collected with smartphones. mHealth researchers should be aware of these factors when designing their studies. The mHealth research community should devise standards for reporting geolocation data quality, analysing systematic differences in data quality between participant groups, and methods for data imputation.

Common and unique associated factors for medically unexplained chronic widespread pain and chronic fatigue.

OBJECTIVE: Chronic widespread pain and chronic fatigue share common associated factors but these associations may be explained by the presence of concurrent depression and anxiety. METHODS: We mailed questionnaires to a randomly selected sample of people in the UK to identify participants with chronic widespread pain (ACR 1990 definition) and those with chronic fatigue. The questionnaire assessed sociodemographic factors, health status, healthcare use, childhood factors, adult attachment, and psychological stress including anxiety and depression. To identify persons with unexplained chronic widespread pain or unexplained chronic fatigue; we examined participant's medical records to exclude medical illness that might cause these symptoms. RESULTS: Of 1443 participants (58.0% response rate) medical records of 990 were examined. 9.4% (N=93) had unexplained chronic widespread pain and 12.6% (N=125) had unexplained chronic fatigue. Marital status, childhood psychological abuse, recent threatening experiences and other somatic symptoms were commonly associated with both widespread pain and fatigue. No common effect was found for few years of education and current medical illnesses (more strongly associated with chronic widespread pain) or recent illness in a close relative, neuroticism, depression and anxiety scores (more strongly associated with chronic fatigue). Putative associated factors with a common effect were associated with unexplained chronic widespread pain or unexplained chronic fatigue only when there was concurrent anxiety and/or depression. DISCUSSION: This study suggests that the associated factors for chronic widespread pain and chronic fatigue need to be studied in conjunction with concurrent depression/anxiety. Clinicians should be aware of the importance of concurrent anxiety or depression.

Clustering of pain and its associations with health in people aged 50†years and older: cross-sectional results from the North Staffordshire Osteoarthritis Project.

OBJECTIVE: Most pain in patients aged ≥50 years affects multiple sites and yet the predominant mode of presentation is single-site syndromes. The aim of this study was to investigate if pain sites form clusters in this population and if any such clusters are associated with health factors other than pain. SETTING: Six general practices in North Staffordshire, UK. DESIGN: Cross-sectional, postal questionnaire, study. PARTICIPANTS: Community-dwelling adults aged ≥50 years registered at the general practices. MAIN OUTCOMES MEASURES: Number of pain sites was measured by asking participants to shade sites of pain lasting ≥1 day in the past 4 weeks on a blank body manikin. Health factors measured included anxiety and depression (Hospital and Anxiety Depression Scale), cognitive complaint (Sickness Impact Profile) and sleep. Pain site clustering was investigated using latent class analysis. Association of clusters with health factors, adjusted for age, sex, body mass index and morbidities, was analysed using multinomial regression models. RESULTS: 13 986 participants (adjusted response 70.6%) completed a questionnaire, of whom 12 408 provided complete pain data. Four clusters of participants were identified: (1) low number of pain sites (36.6%), (2) medium number of sites with no back pain (31.5%), (3) medium number of sites with back pain (17.9%) and (4) high number of sites (14.1%). Compared to Cluster 1, other clusters were associated with poor health. The strongest associations (relative risk ratios, 95% CI) were with Cluster 4: depression (per unit change in score) 1.11 (1.08 to 1.14); cognitive complaint 2.60 (2.09 to 3.24); non-restorative sleep 4.60 (3.50 to 6.05). CONCLUSIONS: These results indicate that in a general population aged ≥50 years, pain forms four clusters shaped by two dimensions-number of pain sites (low, medium, high) and, within the medium cluster, the absence or presence of back pain. The usefulness of primary care treatment approaches based on this simple classification should be investigated.

Self-reported pain severity is associated with a history of coronary heart disease.

BACKGROUND: Previous studies have found an association between chronic pain and cardiovascular (CV) mortality. OBJECTIVE: To explore the relationship between the severity of pain and non-fatal CV disease. METHODS: A total of 45,994 adults randomly selected from general practice registers in Manchester and Aberdeen were posted a survey, which included a Chronic Pain Grade questionnaire, pain manikin and questions about lifestyle and medical history. A single component measuring pain severity was extracted using factor analysis. Logistic regression was used to test for an association between quintiles of pain severity and a history of CV disease, adjusting for confounders. RESULTS: Of the 15,288 responders, 61% (n = 9357) reported pain for ≥ 1 day in the past month. Compared with the first (lowest) pain severity quintile, the fully adjusted odds ratio for heart attack in the second severity quintile was 1.25 (95% confidence interval 0.68, 2.30); third quintile: 1.65 (0.93, 2.94); fourth quintile: 1.76 (1.00, 3.11) and fifth (highest) quintile 2.47 (1.43, 4.28). Corresponding figures for angina (excluding heart attack) were: 1.79 (0.93, 3.45), 1.91 (1.00, 3.62), 1.03 (0.50, 2.11) and 3.17 (1.71, 5.85). CONCLUSION: A history of CV disease is reported more often in those with severe pain than would be expected by chance, even when adjusting for shared risk factors.

Functioning of the hypothalamic-pituitary-adrenal and growth hormone axes in frequently unexplained disorders: results of a population study.

BACKGROUND: The aim of the study was to test the hypothesis that associations with specific stress systems [hypothalamic-pituitary-adrenal (HPA) and growth hormone (GH) axes] would increase as the number of unexplained disorders increased while accounting for the possible confounding effects of psychosocial factors. METHODS: A cross-sectional study identified those reporting chronic widespread pain, irritable bowel syndrome, chronic orofacial pain and chronic fatigue. Of the 1315 subjects, disorder status was available for 1180 (89.7%), of whom 766 (64.9%) reported no disorders, 277 (23.5%) reported one and 137 (11.6%) reported two or more. Eighty subjects were sought from each group for assessment of HPA (morning 8:00 a.m. and evening 10:00 p.m. saliva, and post-dexamethasone serum cortisol levels) and GH [serum insulin-like growth factor 1 (IGF-1) level] axis function. Validated questionnaires informed current psychological state. RESULTS: Two hundred twenty-seven subjects participated [79 (35%) with no disorders, 78 (34%) with one disorder and 70 (31%) with two or more disorders]. There were no significant associations (p < 0.05) between individual disorders or an increasing disorder load with any of the neuroendocrine levels measured: saliva/serum cortisol, IGF-1 and dehydroepiandrosterone. Psychosocial factors were independently associated with disorders and with an increasing disorder load: health anxiety p < 0.01, anxiety p < 0.01, depression p < 0.01, life events p = 0.03. CONCLUSION: Although previous studies have shown that stress axis function acts to moderate the risk of onset of some of these disorders, the present study shows that the degree of dysfunction is not correlated with a corresponding increasing load of disorders. The uncertainty surrounding the role of these biomarkers in the aetiology of unexplained disorders needs further investigation.

Multiple somatic symptoms predict impaired health status in functional somatic syndromes.

BACKGROUND: The relationship between functional somatic syndromes and multiple somatic symptoms is unclear. PURPOSE: We assessed whether the number of somatic symptoms is a predictor of health status in three functional somatic syndromes (FSS). METHODS: In a population-based study of 990 UK adults we assessed chronic widespread pain (CWP), chronic fatigue (CF) and irritable bowel syndrome (IBS) by questionnaire and medical record data. We assessed health status (Short Form 12 and EQ-5D), number of somatic symptoms (Somatic Symptom Inventory) and anxiety/depression (Hospital Anxiety and Depression Scale) both at baseline and at follow-up 1 year later. RESULTS: The proportion of people with an FSS who also have multiple somatic symptoms (52-55 %) was similar in the three functional syndromes. The presence of multiple somatic symptoms was associated with more impaired health status both at baseline and at follow-up. This finding was not explained by severity of FSS. In the absence of multiple somatic symptoms, the health status of the FSS was fair or good. In multiple regression analysis, the number of somatic symptoms, the presence of a functional syndrome (CWP or CF) and anxiety/depression were predictors of EQ-5D thermometer at follow-up after adjustment for confounders. CONCLUSIONS: Multiple somatic symptoms in people with an FSS are associated with impaired health status and this cannot be explained by more severe functional syndrome or the presence of anxiety and depression.

Investigating the role of pain-modulating pathway genes in musculoskeletal pain.

AIMS: The aim of this study was to determine if genetic variation in the pain-modulating gene DREAM and its pathway genes influence susceptibility to reporting musculoskeletal pain in the population. METHODS: Pairwise tag single nucleotide polymorphisms (SNPs) in DREAM, PDYN and OPRK1 were genotyped in a UK population-based discovery cohort in whom pain was assessed using blank body manikins at three time points. Depression and anxiety symptoms were assessed at the first time point. Zero-inflated negative binomial regression was used to test for association between SNPs and the maximum number of pain sites reported (0-29) across the three time points. Significantly associated SNPs (p < 0.05) were subsequently genotyped for validation in a cohort of European men with pain assessed at two time points. RESULTS: Thirty-five SNPs were genotyped in 1055 subjects, of whom 83% reported pain, in the discovery cohort. SNPs in each gene were associated with the maximum number of pain sites reported, were independent of symptoms of anxiety and depression and had a significant cumulative effect (p = 7.0 × 10(-5) ). Significantly associated SNPs were successfully genotyped in 1733 men, 76% of whom reported pain, in the validation cohort, but did not show significant association with the number of pain sites. CONCLUSIONS: Genetic variation in the DREAM pathway genes was associated with the extent of pain reporting in a population-based cohort. These findings were not replicated in a single independent cohort; however, given the potential of this pathway as a therapeutic target, further investigation in additional cohorts is warranted.

A high tender point count is associated with the presence of multiple idiopathic pain disorders: results from a population study.

BACKGROUND/AIMS: To test whether mechanical hyperalgesia is associated with multiple idiopathic pain disorders (IPDs) and whether this relationship is independent of the confounding effects of psychosocial factors. METHODS: One hundred eighteen subjects with chronic orofacial pain (COFP) were identified from their questionnaire responses to a population study in North West England. All subjects had a tender point examination according to the American College of Rheumatology classification. Validated tools on the questionnaire were used to identify presence of other IPDs (irritable bowel syndrome and chronic widespread pain) and psychosocial factors (anxiety, depression, health anxiety, sleep disturbance and reporting of somatic symptoms and adverse life events). RESULTS: Of the 118 subjects, 47.6% (n = 56) had COFP, 34.7% (n = 41) had COFP plus one IPD and 17.8% (n = 21) had all three IPDs. Univariate analysis revealed a dose-response relationship between number of tender points (TPs) and number of IPDs [2-6 TPs (OR 2.6, 95% CI 1.0-7.3), ≥ 7 TPs (OR 10.5, 95% CI 3.8-29.3)] and number of IPDs and psychological distress [anxiety (OR 2.8, 95% CI 1.2-6.4), depression (OR 4.3, 95% CI 1.7-10.6), sleep disturbance (OR 4.8, 95% CI 1.6-14.6)]. The relationship between IPDs and TPs persisted after adjusting for psychosocial factors in multivariate analyses [2-6 TPs (OR 2.5, 95% CI 0.8-7.8) ≥ 7 TPs (OR 10.7, 95% CI 3.4-33.7)]. CONCLUSION: The dose-response relationship between TPs and IPDs needs further investigation to determine the temporal nature of these relationships and to disentangle the complex gene-environment relationships that may influence the occurrence of multiple IPDs.

Chronic widespread pain is associated with slower cognitive processing speed in middle-aged and older European men.

Evidence from clinic-based studies suggests that the fibromyalgia syndrome (FMS) is associated with impairment in cognitive function though the mechanism is unclear. The aim of this analysis was to determine whether there is a similar association between chronic widespread pain (CWP), a cardinal feature of FMS, and impaired cognition in a community setting. Men (n=3369, 40-79 years) were recruited from population registers in eight centres for participation in the European Male Ageing Study (EMAS). The subjects completed a pain questionnaire and pain manikin, with the presence of CWP defined using the American College of Rheumatology criteria. The cognitive functions measured were visuospatial-constructional ability and visual memory (Rey-Osterrieth Complex Figure [ROCF]); visual recognition (Camden Topographical Recognition Memory test [CTRM]); and psychomotor processing speed (Digit-Symbol Substitution test [DSST]). We restricted our analysis to those subjects reporting pain that satisfied the criteria for CWP and those who were pain free. Of these 1539 men [mean (SD) age 60 (11) years], 266 had CWP. All cognitive test scores declined cross-sectionally with age (P<0.05). In age-adjusted linear regressions men with CWP had a lower DSST score (ß=-2.4, P<0.001) compared to pain-free subjects. After adjustment for lifestyle and health factors the association between pain status and the DSST score was attenuated but remained significant (ß=-1.02, P=0.04). There was no association between CWP and the ROCF-copy, ROCF-recall or CTRM scores. CWP is associated with slower psychomotor processing speed among community-dwelling European men. Prospective studies are required to confirm this observation and explore possible mechanisms for the association.

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.

Premorbid psychosocial factors are associated with poor health-related quality of life in subjects with new onset of chronic widespread pain - results from the EPIFUND study.

Chronic widespread pain (CWP) is associated with poor health-related quality of life (HRQoL). It is unclear whether pain itself is the cause of poor HRQoL or other factors play a role. We hypothesised that new onset of CWP was associated with poor physical and mental HRQoL but that psychosocial risk markers for CWP onset would explain this relationship. A prospective population-based survey measured pain and psychosocial status at baseline. Subjects free of CWP at baseline were followed up 15 months later, when pain status, threatening life events and HRQoL (SF-12) were assessed. The risk associated with the new onset of CWP and reporting poor SF12-MCS and SF12-PCS was quantified using multinomial logistic regression (relative risk ratios (RRRs) with 95% confidence intervals (95% CI)), adjusted for age and gender. 3000 subjects (77%) free of CWP at baseline participated at follow-up. 2650 subjects (88%) provided full SF-12 and pain data and formed the cohort for this analysis. 9.4% of subjects (n=248) reported new CWP. New CWP was associated with an increased risk of having the poorest SF12-MCS (RRR=2.3; 95% CI 1.6-3.2) and SF12-PCS (RRR=8.0; 95% CI 5.4-11.8) scores. After adjusting for baseline psychosocial status, the relationship between CWP onset and SF12-MCS was attenuated (RRR=1.2; 95% CI 0.8-1.8), although the association with SF12-PCS remained (RRR=4.8% CI 3.1-7.47). New onset of CWP is associated with poor mental and physical HRQoL. However, the relationship with mental HRQoL is explained by psychosocial risk markers.

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.

Unexplained orofacial pain - is an early diagnosis possible?

Aim To identify distinct characteristics of unexplained orofacial pain that could be used by dental practitioners in making an early diagnosis.Methods Subjects reporting orofacial pain in a postal questionnaire-based cross-sectional survey were invited for clinical examination. The interviewer was blinded to the questionnaire responses of the subjects. A diagnosis was made following the examination and subjects were assigned into two groups: unexplained pain and dental pain. The questionnaire responses of subjects who had consulted a healthcare professional within these two groups were then compared with particular attention to demographics, orofacial pain characteristics, consultation behaviour and relationship with other unexplained syndromes.Results Subjects who had consulted for their pain and were assigned to the unexplained orofacial pain group were significantly (p <0.05) more likely to report the following characteristics: pain descriptors (nagging, aching, tingling), pain pattern (worse with stress), site (poorly localised), duration (persistent/chronic), high disability, multiple consultations and co-morbidities (teeth grinding, reporting of other unexplained syndromes).Conclusion This study has shown that unexplained orofacial pain has distinct characteristics that differentiate it from other common dental conditions. This provides a good evidence base which can reduce uncertainty among dental practitioners, allowing them to make an early diagnosis.

Exploring the genetic susceptibility of chronic widespread pain: the tender points in genetic association studies.

Chronic widespread pain (CWP) is a prevalent disorder associated with a low pain threshold and increased levels of psychological distress. Evidence indicates that there is a genetic component to CWP syndromes and pain sensitivity. Here we have identified and reviewed the current literature on genetic association (GA) studies of CWP and pain sensitivity by searching MEDLINE and EMBASE between January 1990 and May 2007. Of the 18 candidate genes studied to date, no definitive susceptibility genes have been identified. This review highlights the key issues for consideration when interpreting the findings from existing studies and in designing future studies to ensure robust and comparable findings in this field. Well-designed GA studies are essential if the genetic component to CWP aetiology is to be fully determined.

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.

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.

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.

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.