Chronic fatigue in the general population: Prevalence, natural course and associations with chronic pain (the HUNT pain study).

BACKGROUND: Fatigue and pain are both prevalent and frequently co-occur. No standard measure of fatigue exists, but most definitions include a continuum between high levels of energy and fatigue. There is limited knowledge about the course of fatigue in the general population and its association with functioning and other health outcomes. Our main aim was to identify trajectories of energy and fatigue in the general population and to investigate whether chronic pain is related to a negative prognosis of chronic fatigue. METHODS: Longitudinal latent class analysis was performed to classify 4771 individuals into trajectory groups based on five quarterly repeated measures. RESULTS: A five-cluster solution was identified: 'much energy' (n = 1471, [31%]), 'varying energy' (n = 1445, [30%]), 'some energy' (n = 921, [19%]), 'low energy' [chronic moderate fatigue] (n = 852, [18%]) and 'no energy' [chronic severe fatigue] (n = 82, [2%]). Individuals with chronic moderate fatigue who reported chronic pain had reduced probability of improvement over the following 3 years (OR = 0.67, 95% CI [0.52, 0.88]). CONCLUSIONS: Chronic fatigue is highly prevalent in the general population and a small proportion have chronic severe fatigue. When chronic pain co-occurs with chronic fatigue, improvement of chronic fatigue is less likely, indicating that these symptoms may perpetuate each other. SIGNIFICANCE STATEMENT: Understanding the close relationship between chronic pain and chronic fatigue is important as they both contribute to suffering and loss of functioning, may be related to the same underlying diseases, or in the absence of disease, may share common mechanisms. This study highlights the important role of chronic pain in relation to chronic fatigue, both by showing a strong association between the prevalence of the two conditions, and by showing that chronic pain is associated with a negative prognosis of chronic fatigue.

A Clinical Description of Chronic Pain in a General Population Using ICD-10 and ICD-11 (The HUNT Pain Examination Study).

The purpose was to present a total description, distribution, and ranking of chronic pain conditions in the general population. This was based on structured clinical examinations of a random sample from a population-based survey (HUNT3) with a calculated oversampling of participants with chronic pain. Supplemented with access to hospital reports, the examination was performed by experienced physicians and psychologists using a consistent definition of chronic pain as well as ICD-10- and the new ICD-11-classification. The main findings were that a higher proportion of the 551 participants had chronic pain assessed by clinical examination (399) than by self-report in a survey the same day (337). Among those with examination-verified chronic pain estimated from HUNT3 to represent 27.9% of the general population, 63% had chronic primary pain, 81% musculoskeletal pain, and 77% more than one chronic pain condition. When separating chronic primary from chronic secondary pain according to ICD-11, the weighted prevalence was 17.7% for chronic pain conditions of unknown and 10.2% of known cause. When all the participants' conditions were accounted for, the most prevalent was nonspecific low back (10.8%) and neck pain (7.6%). Participants with chronic primary pain did not have significantly more psychopathology than those with chronic secondary pain: 14.5% versus 12.5%. PERSPECTIVE: Since this study confirms the high prevalence in self-report surveys and indicates that two thirds of chronic pain conditions cannot be explained by underlying diseases, this huge health and societal problem should be solved primarily on a public health level directed toward prevention and rehabilitation.

Impact of pain and catastrophizing on the long-term course of depression in the general population: the HUNT pain study.

ABSTRACT: Pain and depression are episodic conditions that might take a chronic course. They are clearly related, but information on how they influence each other in the process of chronification is limited. Pain catastrophizing is hypothesized to play a role in the development of depression and chronic pain, but few longitudinal studies have investigated their association over a longer term. In this study, a random cohort from the general population (n = 4764) answered questions about pain, catastrophizing, and depression at 5 assessments in yearly intervals. Linear mixed models showed that within persons, increases in pain intensity and catastrophizing were independently associated with increases in depressive symptoms {mean change = -1.12, 95% confidence interval (CI) [-1.32 to -0.91] and -1.29, 95% CI [-1.52 to -1.05], respectively}. In prospective analyses restricted to individuals without depression above cutoff at baseline, chronic pain increased the risk of endorsing depression over the following 4 years (odds ratio = 2.01, 95% CI [1.71-2.37]). Seven percent showed a chronic course of depression, as indicated by scores above cutoff on at least 3 of 5 assessments. The number of years lived with chronic pain was associated with a chronic course of depression, with odds ratios increasing from 1.55 (95% CI [0.87-2.91]) to 14.19 (95% CI [8.99-22.41]) when reporting chronic pain on 2 vs 5 assessments compared with none. The results suggest that when pain intensity or catastrophizing change, depressive symptoms change in the same direction. When pain and catastrophizing become chronic, they seem to be mutually reinforcing determinants for chronic depression.

Metacognitive Beliefs as Predictors of Return to Work After Intensive Return-to-Work Rehabilitation in Patients With Chronic Pain, Chronic Fatigue and Common Psychological Disorders: Results From a Prospective Trial.

BACKGROUND: Metacognitions are associated with work status, but no research has examined to what extent metacognitions before treatment and change in metacognitions following treatment predict return to work (RTW) prospectively. The present study aims to address these two gaps in knowledge. METHODS: 212 patients on long-term sick leave (>8 weeks) with extensive fatigue, chronic pain conditions and/or mental distress received 3.5 weeks of intensive rehabilitation treatment, aimed at returning them to work. Only part of the population (n = 137) had complete follow-up data on metacognitions. Metacognitions were measured with the Metacognitions Questionnaire 30 (MCQ-30), while RTW was measured using official registry data from the Norwegian Labor and Welfare Service. A registry record of participation in competitive work ≥2.5 days (50% work participation) per week, averaging over 14 weeks, was chosen as an outcome reflecting a successful RTW. The registry data spanned a total of 56 weeks per participant. RESULTS: Our results indicated that baseline MCQ scores was not associated with RTW. This was analyzed for the total MCQ score as well as for all subscales. We observed substantial changes in metacognitions following treatment, and a 1-point change in the total sum of metacognitive beliefs was associated with 5% greater odds for successful RTW at all time points (p = 0.040), while a 1-point change on the subscale of beliefs about the need to control thoughts gave 20% greater odds for successful RTW (p = 0.016). CONCLUSION: Metacognitions concerning the need to control thoughts appear to have a significant influence on patients return to work. Here, we observed that a change in these beliefs following treatment substantially affected RTW over the course of 1 year.

Novel approach towards musculoskeletal phenotypes.

BACKGROUND: The multidimensional array of clinical features and prognostic factors makes it difficult to optimize management within the heterogeneity of patients with common musculoskeletal pain. This study aimed to identify phenotypes across prognostic factors and musculoskeletal complaints. Concurrent and external validity were assessed against an established instrument and a new sample, respectively, and treatment outcome was described. METHODS: We conducted a longitudinal observational study of 435 patients (aged 18-67 years) seeking treatment for nonspecific complaints in the neck, shoulder, low back or multisite/complex pain in primary health care physiotherapy in Norway. Latent class analysis was used to identify phenotypes based on 11 common prognostic factors within four biopsychosocial domains; pain, beliefs and thoughts, psychological and activity and lifestyle. RESULTS: Five distinct phenotypes were identified. Phenotype 1 (n = 77, 17.7%) and 2 (n = 142, 32.6%) were characterized by the lowest scores across all biopsychosocial domains. Phenotype 2 showed somewhat higher levels of symptoms across the biopsychosocial domains. Phenotype 3 (n = 89, 20.5%) and 4 (n = 78, 17.9%) were more affected across all domains, but phenotype 3 and 4 had opposite patterns in the psychological and pain domains. Phenotype 5 (n = 49, 11.3%) were characterized by worse symptoms across all domains, indicating a complex phenotype. The identified phenotypes had good external and concurrent validity, also differentiating for the phenotypes in function and health-related quality of life outcome at 3-month follow-up. CONCLUSION: The phenotypes may inform the development of targeted interventions aimed at improving the treatment efficiency in patients with common musculoskeletal disorders. SIGNIFICANCE: This observational prospective study identified five distinct and clinically meaningful phenotypes based on biopsychosocial prognostic factors across common musculoskeletal pain. These phenotypes were independent of primary pain location, showed good external validity, and clear variation in treatment outcome. The findings are particularly valuable as they describe the heterogeneity of patients with musculoskeletal pain and points to a need for more targeted interventions in common musculoskeletal disorders to improve treatment outcome.

The Natural Course of Chronic Pain in a General Population: Stability and Change in an Eight-Wave Longitudinal Study Over Four Years (the HUNT Pain Study).

Epidemiological studies have to a little extent addressed the potential fluctuations of chronic pain over time, and there is a lack of information about the long-term course of pain using repeated measurements. We wanted to identify different trajectories of pain during 8 waves of follow-up over 4 years among individuals in the general population reporting pain lasting at least 6 months at baseline. Secondarily, we wanted to investigate whether biopsychosocial factors at baseline were associated with the different pain trajectories. Longitudinal Latent Class Analysis was performed to classify a random sample of 1905 participants from a larger population-based study (HUNT3) into groups based on their longitudinal pain severity reporting. A five-class solution gave the best fit. The terms chosen to describe the pain trajectories were: "fluctuating" (n = 586 [31%]), "persistent mild" (n = 449 [24%]), "persistent moderate" (n = 414 [22%]), "persistent severe" (n = 251 [13%]), and "gradual improvement" (n = 205 [11%]). In a multinomial logistic regression model using "gradual improvement" as the reference category, the "persistent moderate", "persistent severe", and "fluctuating" pain groups were associated with chronic widespread pain, elevated levels of catastrophizing, and poorer mental health. The "persistent mild" group was associated with sleep difficulties only. This study finds that although most individuals have a stable pain course, individuals in the largest distinct trajectory reports pain that fluctuate between mild and moderate levels, thus fluctuating under and above the chronic pain definition using moderate pain or more as a criterion. PERSPECTIVE: When examining the long-term course of chronic pain in the general population, 5 trajectories emerge. Although most individuals have stable pain, the largest distinct trajectory fluctuated under and above the chronic pain cut-off, using moderate pain or more as a criterion. A dichotomous categorization of chronic pain may be overly simplistic.

Anxiety, depression, and function in individuals with chronic physical conditions: A longitudinal analysis.

OBJECTIVE: This longitudinal study examined the unique relationship between anxiety, symptoms (pain intensity, sleep disturbance, fatigue severity), and function domains (self-reported cognitive function, physical function, satisfaction with social roles) in individuals with chronic physical conditions, independent of depressive symptoms. METHOD: Three surveys were mailed on an approximately yearly basis to community-dwelling adults with one of four chronic physical conditions (spinal cord injury, multiple sclerosis, muscular dystrophy, postpoliomyelitis syndrome). The first survey was completed by 1594 individuals (T1). Of these, 1380 completed the second survey (T2), and 1272 completed the third survey (T3). RESULTS: Mixed growth curve models evidenced significant concurrent and longitudinal associations between anxiety and each symptom and function domain, independent of depression severity. The largest unique association found was between anxiety and self-reported cognitive function; inclusion of the measure of anxiety in the model improved model fit substantially over depression alone, χ²[2] = 104.40, p < .001. Both anxiety and depression exhibited similar effect sizes in their unique relationships with each symptom and function domain measure. However, depression was more strongly associated with satisfaction with social roles and physical function than was anxiety. CONCLUSIONS: The findings showed that anxiety assessed at one point in time demonstrated significant and unique associations with concurrent and subsequent symptom and function domains. Given that anxiety has been inadequately studied (and perhaps evaluated and treated) in rehabilitation populations, the current findings suggest that researchers and clinicians should broaden their scope when assessing and treating psychological distress to incorporate anxiety and related disorders. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Catastrophizing, Solicitous Responses From Significant Others, and Function in Individuals With Neuropathic Pain, Osteoarthritis, or Spinal Pain in the General Population.

That certain psychological factors are negatively associated with function in patients with chronic pain is well established. However, few studies have evaluated these factors in individuals with chronic pain from the general population. The aims of this study were to: 1) evaluate the unique associations between catastrophizing and perceived solicitous responses and psychological function, physical function, and insomnia severity in individuals with neuropathic pain, osteoarthritis, or spinal pain in the general population; and 2) determine if diagnosis moderates the associations found. Five hundred fifty-one individuals from the general population underwent examinations with a physician and physiotherapist, and a total of 334 individuals were diagnosed with either neuropathic pain (n = 34), osteoarthritis (n = 78), or spinal pain (n = 222). Results showed that catastrophizing was significantly associated with reduced psychological and physical function, explaining 24% and 2% of the variance respectively, whereas catastrophizing as well as perceived solicitous responding were significantly and uniquely associated with insomnia severity, explaining 8% of the variance. Perceived solicitous responding was significantly negatively associated with insomnia severity. Moderator analyses indicated that: 1) the association between catastrophizing and psychological function was greater among individuals with spinal pain and neuropathic pain than those with osteoarthritis, and 2) the association between catastrophizing and insomnia was greater among individuals with spinal pain and osteoarthritis than those with neuropathic pain. No statistically significant interactions including perceived solicitous responses were found. The findings support earlier findings of an association between catastrophizing and function among individuals with chronic pain in the general population, and suggest that diagnosis may serve a moderating role in some of these associations. PERSPECTIVE: When examining persons with pain in the general population, catastrophizing is associated with several aspects of function, and diagnosis serves as a moderator for these associations. The replication of these associations in the general population support their reliability and generalizability.

Effectiveness of Working Memory Training among Subjects Currently on Sick Leave Due to Complex Symptoms.

Introduction: The current study examined if adaptive working memory training (Cogmed QM) has the potential to improve inhibitory control, working memory capacity, and perceptions of memory functioning in a group of patients currently on sick leave due to symptoms of pain, insomnia, fatigue, depression and anxiety. Participants who were referred to a vocational rehabilitation center volunteered to take part in the study. Methods: Participants were randomly assigned to either a training condition (N = 25) or a control condition (N = 29). Participants in the training condition received working memory training in addition to the clinical intervention offered as part of the rehabilitation program, while participants in the control condition received treatment as usual i.e., the rehabilitation program only. Inhibitory control was measured by The Stop Signal Task, working memory was assessed by the Spatial Working Memory Test, while perceptions of memory functioning were assessed by The Everyday Memory Questionnaire-Revised. Results: Participants in the training group showed a significant improvement on the post-tests of inhibitory control when compared with the comparison group (p = 0.025). The groups did not differ on the post-tests of working memory. Both groups reported less memory problems at post-testing, but there was no sizeable difference between the two groups. Conclusions: Results indicate that working memory training does not improve general working memory capacity per se. Nor does it seem to give any added effects in terms of targeting and improving self-perceived memory functioning. Results do, however, provide evidence to suggest that inhibitory control is accessible and susceptible to modification by adaptive working memory training.