Jürgen Linder

Depression predicts disability in long-term chronic pain patients.

Purpose : Investigators have examined factors that predict treatment outcome and disability status in chronic pain patients, including psychopathology and personality characteristics with equivocal results. The purpose of this study was to evaluate the usefulness of personality characteristics, depression, and personality disorders in predicting disability status in pain patients with long-term follow-up. The setting was a rehabilitation hospital in Southern Sweden. Method : Subjects were 184 pain patients (mean age=43.4 (10.8) years; 72.8% female) who had no more than 365 sick leave days (Mean sick leave days=132.7 (128.2)) prior to the baseline personality and psychiatric evaluation. The baseline evaluation consisted of a psychiatric interview that included the administration of the Structured Clinical Interview for DSM-IV Screen Questionnaire (SCID-II), the Montgomery-Åsberg Depression Rating Scale (MADRS), and the Karolinska Scales of Personality (KSP). Disability status was assessed by insurance record review a minimum of two-and-a-half years after baseline evaluation. Results : Multivariate logistic regression suggests that age (OR=1.09, 95% CI=1.02-1.18; p =0.013), number of sick leave days prior to evaluation (OR=1.01, 95% CI=1.01-1.02; p =0.018), and baseline diagnosis of depression significantly predicted subsequent disability status (OR=7.04, 95% CI=1.15-42.93; p =0.034). Baseline personality traits and the diagnosis of a personality disorder were not useful predictors of disability status in our sample. Conclusions : These data suggest that depression, but not personality disorders characteristics, was an important disability predictor in chronic pain patients with extended follow-up.

The HP5 inventory: definition and assessment of five health- relevant personality traits from a five-factor model perspective

Abstract The aim of the present project was to construct a short personality inventory specifically applicable in personality and health research. The development began with a demarcation of some specific constructs thought to be relevant in explaining individual differences influencing the vulnerability to illness and illness progression as well as psychosocial adaptation to illness. Factor analytic procedures were used separately in two different samples to derive the scales from an item pool. Two confirmation samples were used in addition for cross-validating the final model. In addition, scales from other personality inventories were used to further validate the new scales. A total of 20 items were chosen to constitute the new instrument, entitled the HP5i (H for Health-relevant; P for personality; 5 for its correspondence with the FFM taxonomy; and i for inventory). The five scales were labeled Antagonism (as a facet of Agreeableness), Impulsivity (as a facet of Conscientiousness), Hedonic Capacity (as a facet of Extraversion), Negative Affectivity (as a facet of Neuroticism), and Alexithymia (as a facet of Openness). The new HP5 inventory Scales manifested a meaningful pattern of correlations with NEO PI-R Scales and with two alexithymia scales, thus suggesting some preliminary empirical evidence for convergent validity.

D4 dopamine receptor gene exon III polymorphism and obesity risk.

Many genes have been identified that may play a role in increasing individua susceptibility to obesity. Reduced dopamine function appears to play a role in dysfunctiona eating patterns and may predispose some individuals to obesity. The long version of the D4 dopamine receptor gene (D4DR) has been shown to alter receptor function and reduce intracellular response to dopamine. It also has been associated with novelty-seeking-related personality traits that are found with greater frequency in obese individuals. We examined the association between the long alleles of the D4DR and obesity in a sample of 115 obese patients partici pating in a weight management program. No direct relationship was found between the D4DR and body mass or novelty-seeking-related personality traits. We constructed four models o increased obesity risk that included combinations of traditional risk factors (i.e., long-term history of obesity, parental obesity, a body mass index > 40) and elevations on the novelty-seeking-related scales of the Karolinska Scales of Personality. There was a significant increase in the frequency of the D4DR long alleles in individuals defined as high risk using the combination o novelty-seeking-related personality traits, severe obesity (i.e., BMI > 40), and any other tradi tional risk factor, but not with the traditional risk factors alone. These preliminary data sugges a potential role for the D4DR gene in increasing obesity susceptibility.

Multidisciplinary investigations recognize high prevalence of co-morbidity of psychiatric and somatic diagnoses in long-term sickness absentees

Aims: In Sweden, the Social Insurance Offices each year refer long-term sickness absentees to comprehensive investigations to clarify medical conditions. However, there is a lack of scientific knowledge about these patients and their morbidity. The aim was to characterize a population of these sickness absentees regarding prevalence of somatic and psychiatric diagnoses and possible associations with sociodemographic, lifestyle, and health characteristics. Methods: A cross-sectional study was made up of 635 sickness absentees below the age of 64, who the local Social Insurance Offices in Stockholm County, Sweden, referred to a special unit for multidisciplinary investigation. Data was obtained from questionnaires and medical records. The patients were examined by board certified specialists in psychiatry, orthopaedic surgery, and rehabilitation medicine. Relative risks were estimated by use of modified Poisson regression to assess the associations between characteristics and diagnose outcomes. Results: About 80% of the patients had more than one diagnosis. The vast majority had a psychiatric diagnosis, and approximately 55% had that in combination with at least one somatic diagnosis. An increased risk for being given a psychiatric diagnosis was found for men and unemployed people. In addition, lack of social life and friends and self-reported mental health problems were associated with psychiatric diagnoses but also among those who were given somatic diagnoses in combination with psychiatric diagnoses. Increased risks for somatic diagnoses were found for women and for patients with a higher education. Conclusions: Long-term sickness absentees referred to multidisciplinary investigations display high co-morbidity of psychiatric and somatic diagnoses and are a heterogeneous group with diverse sociodemographic and medical characteristics.

Assessment of Jet Pilots' Upper Trapezius Load Calibrated to Maximal Voluntary Contraction and a Standardized Load

Electromyographic (EMG) recording of the myoelectrical activity level in the trapezius muscle is often used as one method of assessing neck and shoulder muscle workload. To analyse how the normalization value influences interpretation of upper trapezius load during a work task, two different reference values for normalization were applied - one obtained during a maximum voluntary contraction (MVE) and the other during a standardized muscular load (RVE). Nine jet pilots (ages 30-48 yr) flew two sorties in a 37 Viggen aircraft using either of two types of head garment while 3-D acceleration and muscular activity were recorded. In each sortie twice in the programme a steep left turn at 5-6 +G(Z) was performed. The highest activity level (MVE) obtained during shoulder elevation combined with an isometric heavy resistance (maximum) against arm flexion/abduction was used as one normalization value. Before, between, and after the two flights, 15 s EMG recordings (RVE) during a dumbbell test in the same arm position were also taken. The muscular activity in the upper trapezius during a given task varied a great deal between individuals, but the reliability of the amplitude levels on different occasions during a work day was good, given the same electrode location and application. If muscular activity during a standardized loading force (e.g. dumbbell test) is used to normalize the recordings for workload assessments related to utilized muscular capacity, a subject with high muscular strength and comparatively low workload might in some situations be assessed as having the same workload as, or a higher load than a subject with less strength and a comparatively high workload. While normalization using a standardized force can be used to assess changes in workload, for assessing workload related to the individuals capacity recording the myoelectrical activity during maximal contraction is preferable.

Differences in symptoms, functioning, and quality of life between women on long-term sick-leave with musculoskeletal pain with and without concomitant depression

Objective: The aim was to describe the differences in symptoms, functioning and quality of life between women on long-term sick-leave due to protracted musculoskeletal pain with and without concomitant depression. Design: Descriptive and comparisons with/without comorbid depression. Methods: 332 female patients were examined by three specialist physicians in psychiatry, orthopedic surgery, and rehabilitation medicine and assigned to four groups according to the ICD-10 diagnoses: low back/joint disorders (LBJ, n = 150), myalgia (M, n = 43), fibromyalgia (FM, n = 87), or depression without somatic pain diagnosis (DE, n = 52). Results: Patients with somatic pain conditions LBJ, M, or FM showed more activity-related difficulties if concomitant depression was present during the activities ‘focusing attention’, ‘making decisions’, and ‘undertaking a single task’; and in the domains ‘energy level’, ‘memory functions’, ‘emotional functions’, and ‘optimism/pessimism’. Patients with FM and concomitant depression perceived higher pain intensity than patients in group DE. No statistically significant differences in physically related activities were noted between each of the somatic pain conditions with and without coexisting depression. FM patients with coexisting depression reported fewer painful sites on their pain drawings compared with FM-patients without depression. Patients with LBJ or FM and concomitant depression reported lower quality of life in the dimensions vitality, social functioning, emotional role, and mental health. Comorbid depression affected disability and restricted working capacity by reducing mental activity and functioning but not by affecting physical activity problems. Conclusion: Women on long-term sick-leave, who have concomitant depression with LBJ or FM, also have more difficulties in focusing attention, making decisions, and carrying out tasks, and with memory functions and optimism/pessimism, as well as reduced quality of life in the dimensions of vitality, social functioning, emotional role, and mental health, than female patients without comorbid depression. As a consequence we suggest further efforts to integrate somatic and psychiatric interventions in the same rehabilitation program.

Disability, sickness, and unemployment benefits among long-term sickness absentees five years before, during, and after a multidisciplinary medical assessment.

Aim: The aim was to describe how a multidisciplinary medical assessment changed the distribution of long-term sickness absentees between three different forms of social security support during a period of eleven years. Methods: The study group (n = 1002) consisted of persons on long-term sickness absence who were referred to a multidisciplinary medical assessment by the Social Insurance Office in Stockholm, Sweden between 1998 and 2007. Register data from the years 1993–2008 were linked to the study group. A calculation was provided for the number of days per person and year on unemployment benefits, sickness benefits, and disability pension, five years before, during, and five years after the assessment. Also, differences in the average number of days per person and year were calculated with one-way analysis of variance. Results: The number of days on sickness benefits increased up to the time of multidisciplinary medical assessment, from 69 to 218 days on average. After the assessment there was a decrease in the average number of days on sickness benefits, from 218 to 16 days. Before the assessment the number of days on disability pension was 21, but this increased after the assessment from 104 days to an average of 272 days five years after the assessment. There were age differences regarding number of compensated days, and these were particularly pronounced for disability days after the assessment. Further, there were significant differences between types of diagnosis in relation to average days on disability pension after the assessment. Conclusion: The study shows that after a multidisciplinary medical assessment there is a rapid increase in disability pension and a dramatic decrease in sickness benefits. The results indicate that for a large number of persons, a Social Insurance Office referral to an assessment does not improve their chances of returning to work, but rather seems to justify disability pension.

Does multidisciplinary assessment of long-term sickness absentees result in modification of sick-listing diagnoses?

Aims: The aim was to study whether sick-leave diagnoses of long-term sickness absentees were modified after a multidisciplinary assessment and if modifications differed with type of medical specialty of the latest physician to sick-list the patient. Methods: A sample of 635 long-term sickness absentees referred to a multidisciplinary assessment by Social Insurance Offices was included. Data were obtained through sickness certificates and medical records. Patients were examined by board-certified specialists in psychiatry, orthopaedic surgery, and rehabilitation medicine. Descriptive statistics were used. Results: The multidisciplinary assessment resulted in an increase from 1—2 to 2—3 diagnoses for most patients. Forty-five per cent of the male and 47% of the female patients had only somatic diagnoses at referral. After the multidisciplinary assessment these percentages were 20% and 29%, respectively. The rate of women and men given both psychiatric and somatic diagnoses increased from 30% at referral to about 55%. The shift from either only psychiatric or only somatic diagnoses to having these diagnoses in combination was associated with type of specialty of the physician who had sick-listed the patient. Conclusions: The study indicates that many patients on long-term sick-leave with unclear diagnoses may suffer from unrecognized, and therefore probably untreated, medical disorders and co-morbidity.

Outcome of multidisciplinary investigations of long-term sickness absentees.

Objective. The aim was to investigate the results of multidisciplinary investigations of long-term sickness absentees regarding diagnoses, degree and prognoses of work incapacity, and need of rehabilitation measures and whether this was associated with socio-demographic factors. Method. A cross-sectional study of 545 long-term (>1 year) sickness absentees referred to multidisciplinary investigations by the Social Insurance Office. Data was obtained from questionnaires and medical records. The patients were examined by specialists in psychiatry, orthopaedic surgery, and rehabilitation medicine who afterwards agreed on diagnoses, work incapacity, time to return to work (RTW), and rehabilitation measures. Descriptive statistics and logistic regression were used for description and analyses of data. Data on age, country of birth, education, employment and marital status were included. Results. The prevalence of psychiatric diagnoses was 72%, and 58% of the patients had that in combination with somatic diagnoses. Most patients were assessed to be capable of RTW within 6 – 24 months after further rehabilitation measures. Higher age was associated with a negative prognosis of RTW and those patients were less often recommended additional rehabilitation. Conclusion. Despite long-term sickness absence and high rates of psychiatric and somatic diagnoses in combination, RTW was considered possible for most patients after further rehabilitation measures.

PSYCHOLOGICAL FACTORS ARE RELATED TO RETURN TO WORK AMONG LONG-TERM SICKNESS ABSENTEES WHO HAVE UNDERGONE A MULTIDISCIPLINARY MEDICAL ASSESSMENT

OBJECTIVE To assess the associations between psychological factors and return to work among long-term sickness absentees. DESIGN Longitudinal study with a 3-year follow-up. SUBJECTS Long-term sickness absentees (n = 905) who had undergone a multidisciplinary medical assessment. METHODS Three years after multidisciplinary medical assessment, return to work status (full, partial, or none) was determined according to whether the individuals received full, partial, or no sickness benefits. Multinomial logistic regression analyses were performed to assess the odds ratios with 95% confidence intervals for return to work related to indecision, lassitude, fatigability, reduced sleep, social functioning, emotional role limitations, and vitality. RESULTS After adjusting for socio-demographic factors and medical diagnoses most of the studied psychological factors were significantly associated with full (odds ratios 2.13-1.50) and partial (odds ratios 2.25-1.63) return to work in the follow-up period. Low level of lassitude was associated with full return to work (odds ratio 1.72) even when the other psychological factors were controlled for. Similarly, low fatigability was associated with partial return to work (odds ratio 1.81). CONCLUSION This study indicates that psychological factors are important for both full and partial return to work among long-term sickness absentees who have undergone a multidisciplinary medical assessment.