General practitioners' stay-at-work practices in patients with musculoskeletal disorders: using Intervention Mapping to develop a training program.

OBJECTIVES: To describe current stay-at-work practices among Danish general practitioners (GPs) in relation to patients with musculoskeletal disorders, to identify potential avenues for improvement, and to suggest a training program for the GPs. DESIGN AND SETTING: We followed the principles of Intervention Mapping. Data were collected by means of literature searches, focus group interviews with GPs, and interaction with stakeholder representatives from the Danish labour market. RESULTS: GPs' current stay-at-work practices were influenced by systemic, organisational, and legislative factors, and by personal determinants, including knowledge and skills relating to stay-at-work principles and musculoskeletal disorders, recognition of the patient's risk of long-term work disability, their role as a GP, and expectations of interactions with other stay-at-work stakeholders. GPs described themselves as important partners and responsible for the diagnostic and holistic assessments of the patient but placed themselves on the side line relying on the patient or workplace stakeholders to act. Their practices are influenced both by patients, employers, and by other stakeholders. We propose a training course for GPs that incorporate both concrete tools and behaviour change techniques. CONCLUSIONS: We have identified varied perspectives on the roles and responsibilities of GPs, as well as legislative and organisational barriers, and proposed a training program. Not all barriers identified can be addressed by a training course, and some questions are left unanswered, among others - who are best suited to help patients staying at work?

Musculoskeletal disorders are highly prevalent and one of the most common causes for visiting a GP.In many countries, GPs are important in facilitating that patients stay at work, when they are experiencing musculoskeletal pain and disability.In our research, GPs place themselves on the side line as coaches relying on the patient or workplace to act.Barriers such as role identity, systemic and organisational issues prevent GPs from being more involved in stay-at-work practices.GPs' with knowledge about stay-at-work practices may empower patients to better self-management.

Motor skills at 7 years of age and spinal pain at 11 years of age: a cohort study of 26,000 preadolescents.

This study aims to investigate the relationship between motor skills at age 7 and spinal pain at age 11. The study included participants from the Danish National Birth Cohort. Data on motor skills were obtained from the Developmental Coordination Disorder Questionnaire, completed by the mothers when the children were 7 years old, and spinal pain was self-reported at age 11 for frequency and intensity of neck, mid back, and low back pain. This was categorized into "no," "moderate," or "severe" pain, based on frequency and pain intensity. Associations were estimated using multinomial logistic regression models. Data on both motor skills and spinal pain was available for 25,000 children. There was a consistent pattern of reporting more neck or mid back pain at age 11 for those with lower levels of fine motor skills and coordination scores at age 11. The relationship was significant for severe pain (the highest relative risk ratio being 1.87 and the lowest 1.18), but not for moderate pain (the highest relative risk ratio being 1.22 and the lowest 1.07). Gross motor skills were not associated with spinal pain, and there was no relationship between low back pain and motor skills.  Conclusion: Our results indicate a link between motor development at 7 years of age and neck and mid back pain, but not low back pain, at 11 years of age. Improvement of motor skills in young children might reduce the future burden of neck and mid back pain and should be a target of future research. What is Known: • Spinal pain in preadolescence and adolescence is common and predisposes to spinal pain in adulthood. • Motor skills influence the biomechanics of movement and therefore has a potential impact on musculoskeletal health. What is New: • Poor fine motor- and coordination skills in childhood were associated with increased risk of severe neck- or mid back pain, but not low back pain, four 4 years later. • Poor gross motor skills were not associated with higher risk of later spinal pain.

Symptoms of lumbar spinal stenosis in people with knee or hip osteoarthritis or low back pain: a cross-sectional study of 10,234 participants in primary care.

OBJECTIVE: The aims of this study were to evaluate: the proportion of people reporting symptoms associated with lumbar spinal stenosis (LSS) in primary care programs for knee or hip osteoarthritis (OA) or persistent low back pain (LBP) and; the prevalence of self-reported clinical LSS in these three cohorts, according to two sets of adapted criteria. METHOD: A cross-sectional analysis of baseline data from the Good Life with osteoArthritis in Denmark primary care programs. Self-report LSS symptom questions were administered to participants with knee OA, hip OA, and persistent LBP. The prevalence of eleven LSS symptoms and clinical LSS were calculated for each cohort. RESULTS: A total of 10,234 participants were included in the analysis. A similar proportion of participants in each cohort were female (69%), with a 6- and 7-year older mean age in the knee and hip cohorts compared to the back cohort. A greater proportion of participants with LBP reported LSS symptoms (range 11-71%) than in the hip (11-50%) and knee (8-40%) cohorts. This pattern was observed for all but one symptom. The same pattern was observed for the prevalence of clinical LSS with less than 10% of people in each cohort satisfying the clinical criteria. CONCLUSION: Self-reported LSS symptoms are commonly reported by people treated in primary care for knee or hip OA, although not as frequently as reported by those with LBP. Despite symptoms of LSS being common, only a small proportion of people were classified as having self-reported clinical LSS.

The patient enablement instrument for back pain: reliability, content validity, construct validity and responsiveness.

BACKGROUND: Currently, there are no outcome measures assessing the ability of people with non-specific low back pain to self-manage their illness. Inspired by the 'Patient Enablement Instrument', we developed the Patient Enablement Instrument for Back Pain (PEI-BP). The aim of this study was to describe the development of the Patient Enablement Instrument for Back Pain (PEI-BP) and investigate content validity, construct validity, internal consistency, test-retest reliability, measurement error, responsiveness and floor and ceiling effects. METHODS: The PEI-BP consists of 6 items that are rated on a 0-10 Numeric Rating Scale. Measurement properties were evaluated using the COSMIN taxonomy and were based on three cohorts from primary care with low back pain: The content validity cohort (N = 14) which participated in semi-structured interviews, the GLA:D® Back cohort (N = 272) and the test-retest cohort (N = 37) which both completed self-reported questionnaires. For construct validity and responsiveness, enablement was compared to disability (Oswestry Disability Index), back pain beliefs (Brief Illness Perception Questionnaire), fear avoidance (Fear-Avoidance Beliefs Questionnaire-physical activity), mental health (SF-36), educational level and number of previous episodes of low back pain. RESULTS: The PEI-BP was found to have acceptable content validity, construct validity, reliability (internal consistency, test-retest reliability and measurement error) and responsiveness. The Smallest Detectable Change was 10.1 points illustrating that a patient would have to change more than 1/6 of the scale range for it to be a true change. A skewed distribution towards the high scores were found at baseline indicating a potentially problematic ceiling effect in the current population. CONCLUSIONS: The PEI-BP can be considered a valid and reliable tool to measure enablement on people seeking care for non-specific LBP. Further testing of the PEI-BP in populations with more severe LBP is recommended. TRIAL REGISTRATION: Not applicable.

The feasibility of implementing an English language version of GLA:D Back.

BACKGROUND: Evidenced-based clinical guidelines for the treatment of low back pain (LBP) consistently suggest educating patients about their back pain, its natural course, and providing advice to keep active and continue working. Despite this evidence, clinicians routinely do not follow these recommendations resulting in ineffective and fragmented care. GLA:D® Back, a standardized care package, was originally developed in Denmark to assist clinicians in implementing evidence-based care. This study will evaluate the feasibility of implementing the English version of the Danish GLA:D® Back program in Alberta, Canada. METHODS: Thirty-five clinicians from nineteen clinics in Alberta, Canada, participated. Feasibility of program implementation, our primary objective, was evaluated within 3 months. Feasibility success was defined as 50% clinician/clinic adoption in addition to 66-88 enrolled participants registered in the database. Our secondary objectives included collecting data pertaining to clinician confidence, attitudes and behaviour of treating patients, perceived barriers and facilitators of program in addition to collecting patient-data regarding pain, function, general health and self-efficacy. RESULTS: The majority of the clinics (15/19, 79%) offered GLA:D® Back to their patients within the study period. Of the participating clinicians, GLA:D® Back was delivered by (25/35, 71%) of clinicians. In total, 78 patients were enrolled in the program and (69/78, 88%) participants attended the final assessment. Secondarily, clinicians demonstrated a biomedical and behavioural orientation along with high confidence when treating LBP patients while patient outcomes trended toward improvement. CONCLUSION: The English translation of the Danish GLA:D Back program was feasible for Albertan clinicians to implement into practice in both urban and rural settings.

Is this back pain killing me? All-cause and cardiovascular-specific mortality in older Danish twins with spinal pain.

BACKGROUND: Few studies have examined the potentially reduced life expectancy associated with spinal pain (i.e. low back and neck pain) in an ageing population, particularly after controlling for familial factors, including genetics. METHODS: We investigated whether spinal pain increased the rate of all-cause and disease-specific cardiovascular mortality in older Danish twins aged ≥70 years. Data from 4391 participants collected at baseline were linked with the Danish Cause of Death Registry with the study ending on 31 December 2014. Two crude and adjusted Cox proportional hazards regression analyses determined the rate of all-cause and disease-specific cardiovascular mortality by baseline spinal pain exposure; unpaired (total sample analysis) and twin pair (intra-pair analysis). Analyses were also adjusted for confounders; baseline physical functional ability and depressive symptoms. Competing risk regression models determined the rate of cardiovascular mortality, adjusting for similar confounders and using the total sample only. RESULTS: Spinal pain was associated with an increased rate of all-cause mortality, hazard ratio (HR): 1.13 [95% confidence interval (CI): 1.06-1.21]. There was no association between spinal pain and cardiovascular disease mortality, sub-distribution hazard ratio (SHR): 1.08 [95% CI 0.96-1.21]. After adjusting for confounders (physical functional ability and depressive symptoms), the association became non-significant. All intra-pair analyses were statistically non-significant, although greater in magnitude for monozygotic twins. CONCLUSIONS: Older people reporting spinal pain have 13% increased risk of mortality per years lived but the connection is not causal. We found no association between spinal pain and cardiovascular-specific mortality. The influence of shared familial factors is unlikely. SIGNIFICANCE: Older people reporting spinal pain have 13% increased risk of mortality per year lived. However, this association is not likely to be causal, with the relevant confounders contributing to this relationship. Thus, pain in the spine may be part of a pattern of poor health, which increases mortality risk in the older population.

Incidence and prognosis of mid-back pain in the general population: A systematic review.

BACKGROUND AND OBJECTIVE: Despite being common early in life and affecting individuals' quality of life to the same degree as neck and low back pain, research into epidemiological aspects of mid-back pain (MBP) has been scarce. The purpose of our systematic review was therefore to describe the incidence and prognosis of MBP in the general population. The PRISMA Statement guided the study process. DATABASES: A systematic search was conducted in CINAHL, PEDro, PsycINFO and Scopus. RESULTS: Of 3194 unique records identified, seven were included in our qualitative synthesis. The 3-month and 2-year incidence proportions of MBP in children and adolescents were approximately 4% and 50%, respectively. In adults, the 1-month incidence proportion was less than 1%. The persistence or recurrence of MBP over a 1- to 4-year period was between 13% and 45% in children and adolescents; a change in spinal pain location over time was common. Individuals reporting MBP have an increased risk of future care seeking compared with people without musculoskeletal complaints. No studies assessing adult MBP recovery trajectories or prognostic factors were identified. CONCLUSIONS: Knowledge about the incidence and prognosis of MBP in the general population is limited. The incidence of MBP in children and adolescents seems to be similar to the incidence of neck and low back pain; in adults, it is lower than that of neck and low back pain. Studies investigating recovery trajectories of MBP in adults and prognostic factors for MBP are lacking. WHAT DOES THIS STUDY ADD?: The incidence of mid-back pain (MBP) in young individuals is similar to that of neck and low back pain, and ≤50% report persistent pain; however, the evidence base is limited. Knowledge about adult trajectories and prognostic factors for MBP is lacking.

No associations between objectively measured physical activity and spinal pain in 11-15-year-old Danes.

BACKGROUND: Physical activity is thought to play a role in spinal pain (neck pain, mid back pain, low back pain) in children and adolescents, either as a risk or protective factor, but current evidence is conflicting. The overall aim of this study was to determine the cross-sectional and longitudinal associations between different levels of objectively measured physical activity, i.e. sedentary; moderate and vigorous; vigorous physical activity, and spinal pain in 11-15-year-old Danes. METHODS: Data were collected at baseline (2010) (n = 906) and at follow-up 2 years later (n = 625) in a school-based prospective cohort study. Physical activity was measured using the Actigraph GT3X Triaxial Activity Monitor, which measures the intensity of physical activity over time. This was worn for 1 week and spinal pain was assessed via e-survey that participants completed during school time. Potential confounders included in the multivariable analyses were sex, anthropometry, physical fitness, social status and psychosocial factors. In the longitudinal study, analyses stratified by baseline pain status were performed. RESULTS: There were neither cross-sectional nor longitudinal associations between different levels of objectively measured physical activity and spinal pain over the 2-year period. CONCLUSION: Objectively measured physical activity was not associated with spinal pain. However, it remains to be seen whether there is an association over a longer follow-up period. Future research should focus on the more qualitative aspects of physical activity, such as different sports activities.

A population-based, incidence cohort study of mid-back pain after traffic collisions: Factors associated with global recovery.

BACKGROUND: Traffic collisions often result in a wide range of symptoms included in the umbrella term whiplash-associated disorders. Mid-back pain (MBP) is one of these symptoms. The incidence and prognosis of different traffic injuries and their related conditions (e.g. neck pain, low back pain, depression or others) has been investigated previously; however, knowledge about traffic collision-related MBP is lacking. The study objectives were to describe the incidence, course of recovery and prognosis of MBP after traffic collisions, in terms of global self-reported recovery. METHODS: Longitudinal data from a population-based inception cohort of all traffic injuries occurring in Saskatchewan, Canada, during a 2-year period were used. Annual overall and age-sex-specific incidence rates were calculated, the course of recovery was described using the Kaplan-Meier technique, and associations between participant characteristics and time-to-self-reported recovery were explored in 3496 MBP cases using Cox proportional hazards models. RESULTS: The yearly incidence rate was 236 per 100,000 population during the study period, and was highest in women and in young persons. The median time-to-first reported recovery was 101 days (95% CI: 99-104) and about 23% were still not recovered after 1 year. Participant's expectation for recovery, general health, extent of severely affecting comorbidities and having experienced a previous traffic injury were some of the prognostic factors identified. CONCLUSIONS: These findings show that MBP is common after traffic collisions, may result in a long recovery process and that a range of biopsychosocial factors are associated with recovery.

Patient education with or without manual therapy compared to a control group in patients with osteoarthritis of the hip. A proof-of-principle three-arm parallel group randomized clinical trial.

OBJECTIVE: To investigate the effectiveness of a patient education (PE) program with or without the added effect of manual therapy (MT) compared to a minimal control intervention (MCI). METHODS: In a single-center university hospital setting, a total of 118 patients with clinical and radiographic unilateral hip osteoarthritis (OA) from primary care were randomized into one of three groups: PE, PE plus MT or MCI. The PE was taught by a physiotherapist involving five sessions. The MT was delivered by a chiropractor involving 12 sessions and the MCI included a home stretching program. Primary outcome was self-reported pain severity on an 11-box numeric rating scale (NRS) immediately following a 6-week intervention period. Patients were followed for 1 year. RESULTS: Primary analysis included 111 patients (94%). In the combined group (PE + MT), a clinically relevant reduction in pain severity compared to the MCI of 1.90 points (95% confidence interval (CI) 0.9-2.9) was achieved. Effect size (Cohen's d) for the PE + MT minus the MCI was 0.92 (95% CI 0.41-1.42). Number needed to treat for PE + MT was 3 (95% CI 2-7). No difference was found between the PE and MCI groups, with mean difference 0.0 (95% CI -1.0 to 1.0). At 12 months, not including patients receiving hip surgery the statistically significant difference favoring PE + MT was maintained. CONCLUSIONS: For primary care patients with OA of the hip, a combined intervention of MT and PE was more effective than a MCI. PE alone was not superior to the MCI. TRIAL REGISTRATION: clinicaltrials.govNCT01039337.

Patterns of musculoskeletal pain in the population: a latent class analysis using a nationally representative interviewer-based survey of 4817 Danes.

BACKGROUND: Pain from the musculoskeletal system often occurs in more than one site. This appears to affect prognosis negatively. Knowledge about specific pain patterns is lacking. OBJECTIVES: To define specific patterns of musculoskeletal co-complaints occurring alongside a primary musculoskeletal complaint. METHODS: Using data from an interview-based health survey of a nationally representative sample of the adult Danish population in 1991 (n = 4817), we describe the co-occurrence of musculoskeletal complaints. Using latent class analysis, we identify clusters of musculoskeletal complaints. RESULTS: Forty percent reported a complaint during a 2-week period; the most common being the low back, neck, shoulder, and knee, and 40% reported more than one complaint. Two latent classes were found for each of the nine primary pain sites except for the low back where three were found. For all primary pain areas, the largest class had site-specific pain only, whereas the smallest class had diffuse pain covering large parts of the body. For participants with a primary musculoskeletal complaint in the spine, the highest probabilities for co-complaints were at other sites in the spine. For primary complaints in the extremities, co-complaints occurred most commonly at adjacent areas. One noticeable exception was a primary complaint of knee pain where co-complaints were found in more remote areas as the neck and low back. CONCLUSIONS: Unique clusters of musculoskeletal co-complaints can be determined based on primary pain site. These patterns are different for persons with a primary complaint in the spine compared with persons with a primary complaint in the extremities.

Heritability of neck pain: a population-based study of 33,794 Danish twins.

OBJECTIVES: To determine the heritability of neck pain in a large population-based study of twins. METHODS: Data on lifetime prevalence of neck pain from a population-based cross-sectional survey of Danish twins were used. To assess twin similarity, the probandwise concordance rates, zygosity-specific odds ratios and tetrachoric correlations were calculated and compared for monozygotic and dizygotic twins. Using biometric modelling (structural equation modelling), the genetic and environmental contributions of the liability to neck pain were estimated. RESULTS: A total of 33,794 twins (response rate 73%) answered the questions regarding neck pain. Probandwise concordance rates, zygosity-specific odds ratios and tetrachoric correlations showed a significant genetic effect on neck pain. An overall additive genetic component of 44% was found. The genetic effect decreased with age, accounting for only 10% in the oldest male group and 0% in the oldest female group. There was a statistically significant difference in heritability between males and females (34 vs 52%, P<0.0001). CONCLUSIONS: Genes play a significant role in neck pain, particularly in women. However, the genetic influence becomes gradually less important with increasing age, and environmental factors dominate almost completely in the older age groups.

Intensive education combined with low tech ergonomic intervention does not prevent low back pain in nurses.

AIMS: To evaluate the effectiveness of an intensive educational and low-tech ergonomic intervention programme aimed at reducing low back pain (LBP) among home care nurses and nurses' aids. METHODS: In 1999, 345 home care nurses and nurses' aids in four Danish municipalities were studied. Participants in two municipalities constituted the intervention group and participants in the other two served as the control group. In the intervention group, participants were divided into small groups, each of which was assigned one specially trained instructor. During weekly meetings participants were educated in body mechanics, patient transfer, and lifting techniques, and use of low-tech ergonomic aids. In the control group, participants attended a one time only three hour instructional meeting. Information on LBP was collected using the Standardised Nordic Questionnaire supplemented with information on number of episodes of LBP and care seeking due to LBP during the past year. RESULTS: A total of 309 nurses and nurses' aids returned the questionnaire at baseline and 255 at follow up in August 2001. At follow up, no significant differences were found between the two groups for any of the LBP variables, and both groups thought that education in patient transfer techniques had been helpful. Within group changes in LBP status was not related to the intervention or to satisfaction with participating in the project. CONCLUSIONS: Intensive weekly education in body mechanics, patient transfer techniques, and use of low-tech ergonomic equipment was not superior to a one time only three hour instructional meeting for home care nurses and nurses' aids.

Psychosocial factors at work in relation to low back pain and consequences of low back pain; a systematic, critical review of prospective cohort studies.

Relevant studies of low back pain (LBP) published between 1990 and 2002 were systematically retrieved via electronic databases and checking of reference lists. Forty papers fulfilled the inclusion criteria; 10 were of high quality. A wide variety of instruments had been used for collection of data on work related psychosocial factors, many of which had not undergone any form of validation. Moderate evidence was found for no association between LBP and perception of work, organisational aspects of work, and social support at work. There was insufficient evidence for a positive association between stress at work and LBP. No conclusions could be drawn regarding perception of work and consequences of LBP. There was strong evidence for no association between organisational aspects of work and moderate evidence for no association between social support at work and stress at work and consequences of LBP.

Ambiguous relation between physical workload and low back pain: a twin control study.

AIMS: To examine the association between self reported physical workload and low back pain (LBP) in younger twins. To investigate whether genetic factors interact with physical workload in relation to LBP. METHODS: A twin control study was performed within a population based twin register using 1910 complete monozygotic (MZ) and same sexed dizygotic (DZ) twin pairs aged 25-42 and discordant for LBP. LBP in the affected twins was divided into two groups: "LBP for 30 days during the past year". Physical workload was divided into four categories: "sitting", "sitting/walking", "light physical", and "heavy physical". Data were analysed in a matched design using conditional logistic regression. MZ and DZ twins were analysed separately and together in order to determine possible genetic influences in relation to physical workload and LBP. RESULTS: Statistically significant graded relations were found for increasing workload and LBP of longer duration but not for LBP of shorter duration (

The association between physical workload and low back pain clouded by the "healthy worker" effect: population-based cross-sectional and 5-year prospective questionnaire study.

STUDY DESIGN: A population-based cross-sectional and 5-year prospective questionnaire study. OBJECTIVE: To investigate self-reported physical workload as a risk factor for low back pain. SUMMARY OF BACKGROUND DATA: Both physical and psychosocial workplace factors are considered risk factors for low back pain. However, today no consensus has been reached regarding the exact role of these factors in the genesis of low back pain. METHODS: Questionnaire data were collected at baseline for 1397 (and after 5 years for 1163) men and women aged 31--50 years at baseline. Low back pain ("any low back pain within the past year," "low back pain < or = 30 days in total during the past year," "low back pain > 30 days in total during the past year") was analyzed in relation to physical workload (sedentary, light physical, and heavy physical work) using logistic regression and controlling for age, gender, and social group. The proportions of workers changing between the workload groups over the 5-year period were analyzed in relation to low back pain status. RESULTS: At baseline no statistically significant differences in low back pain outcomes were found for workers exposed to sedentary, light physical, or heavy physical work. This was true for all age, gender, and social groups. At follow-up there was a statistically significant dose-response association between any low back pain and longstanding low back pain within the past year and increasing physical workload at baseline also after controlling for age, gender, and social group. Subjects with heavy physical workload at baseline changed statistically significantly more often to sedentary work if they experienced low back pain for more than 30 days out of the past year. CONCLUSIONS: Having a sedentary job might have a protective or neutral effect in relation to low back pain, whereas having a heavy physical job constitutes a significant risk factor. Because of migration between exposure groups (the "healthy-worker" effect), longitudinal studies are necessary for investigating the associations between physical workload and low back pain.

Is sitting-while-at-work associated with low back pain? A systematic, critical literature review.

OBJECTIVES: To present a critical review and evaluate recent reports investigating sitting-while-at-work as a risk factor for low back pain (LBP). METHODS: The Medline, Embase and OSH-ROM databases were searched for articles dealing with sitting at work in relation to low back pain for the years 1985-97. The studies were divided into those dealing with sitting-while-working and those dealing with sedentary occupations. Each article was systematically abstracted for core items. The quality of each article was determined based on the representativeness of the study sample, the definition of LBP, and the statistical analysis. RESULTS: Thirty-five reports were identified, 14 dealing with sitting-while-working and 21 with sedentary occupations. Eight studies were found to have a representative sample, a clear definition of LBP and a clear statistical analysis. Regardless of quality, all but one of the studies failed to find a positive association between sitting-while-working and LBP. High quality studies found a marginally negative association for sitting compared to diverse workplace exposures, e.g. standing, driving, lifting bending, and compared to diverse occupations. One low quality study associated sitting in a poor posture with LBP. CONCLUSIONS: The extensive recent epidemiological literature does not support the popular opinion that sitting-while-at-work is associated with LBP.

Coding of occupation for the "young cohort" of the Danish twin register. A resource for future epidemiologic research.

OBJECTIVES: Information on health-related outcomes and exposures is available in user-friendly computerized format for the "young cohort" of the Danish Twin Register born 1953-82. We incorporated occupation information within the database to facilitate future job-related studies. METHODS: Occupation information for the 29,430 twins responding to a mailed questionnaire in 1995 was coded according to DISCO-88. The subjects were classified in three ways depending on the information available: directly from the 2,196 job titles listed in the DISCO-88 handbook, according to a set of predetermined rules, or by consensus if ambiguous information was provided. Two percent (2%) of the sample was recoded independently by two investigators to demonstrate coding consistency. RESULTS: Occupation could be directly coded using job titles for 61% of the sample; 15% were coded according to a set of rules or by consensus; 24% could not be coded. The recoded sample was 99% in agreement with the original coding. CONCLUSION: Occupation information has been incorporated within the extensive health-related database for the "young cohort" of the Danish Twin Register. This resource is available to researchers for future studies concerning occupation, health, and heredity using (1) the existing data (2) via linkage to other Danish databases, or (3) by contacting selected subjects directly.