Heiner Raspe

Back pain in the German adult population: prevalence, severity, and sociodemographic correlates in a multiregional survey.

Study Design. A population-based cross-sectional multiregion postal survey. Objective. To provide a descriptive epidemiology of the prevalence and severity of back pain in German adults and to analyze sociodemographic correlates for disabling back pain within and across regions. Summary of Background Data. Back pain is a leading health problem in Germany. However, comprehensive population-based evidence on the severity of back pain is still fragmentary for this country. Despite earlier findings concerning large prevalence differences across regions, systematic explanations remain to be ascertained. Methods. Questionnaire data were collected for 9263 subjects in 5 German cities and regions (population-based random samples, postal questionnaire). Point, 1-year, and lifetime prevalence were assessed using direct questions, and graded back pain was determined using the Graded Chronic Pain Scale. Poststratification was applied to adjust for cross-regional sociodemographic differences. Results. Point-prevalence was 37.1%, 1-year prevalence 76.0%, and lifetime prevalence 85.5%. A substantial minority had severe (Grade II, 8.0%) or disabling back pain (Grade III–IV, 11.2%). Subjects with a low educational level reported substantially more disabling back pain. This variable was an important predictor for large cross-regional differences in the burden of back pain. Conclusion. Back pain is a highly prevalent condition in Germany. Disabling back pain in this country may be regarded as part of a social disadvantage syndrome. Educational level should receive greater attention in future cross-regional comparisons of back pain.

Influence of occupational factors on the relation between socioeconomic status and self-reported back pain in a population-based sample of German adults with back pain

STUDY DESIGN Population-based cross-sectional postal survey and interview substudy. OBJECTIVES To examine the association between socioeconomic status and severe back pain and to determine whether this association can be explained by occupational factors. SUMMARY OF BACKGROUND DATA Like other disorders, back pain and its consequences are inversely related to indicators of high socioeconomic status. METHODS The associations between indicators of socioeconomic status and presence or severity of current back pain (no back pain or back pain of low intensity and low disability versus back pain with high intensity and/or high disability) were investigated in a survey among German adults 25 to 74 years of age (n = 2731) and an interview substudy of 770 participants with a recent history of back pain.- RESULTS In the survey, educational level was inversely associated with back pain and severe current back pain. Similarly, in the interview substudy, educational level, vocational training, occupational class, household income, and health insurance status were inversely related to severe current back pain. Age-adjusted and gender-adjusted odds ratios were 0.36 (95% confidence interval [CI] 0.25-0.52) for immediate educational level and 0.37 (95% CI 0.18-0.73) for high educational level. Recalled work tasks at the onset of back pain were significant risk factors of severe current back pain (heavy physical work: odds ratio [OR] 1.77, 95% CI 1.06-2.93; work in bent position among males: OR 1.89, 95% CI 1.03-3.46). After adjusting for occupational class or work tasks, the association between educational level and severe current back pain remained unchanged.- CONCLUSIONS The findings support the hypothesis that severe back pain is less prevalent among adults of higher socioeconomic status. The underlying mechanism could not be explained by differences in self-reported occupational factors.

Course and prognosis of back pain in primary care: The epidemiological perspective

The paper by Enthoven et al. in the current edition of Pain (ref) is the latest study in which the techniques of epidemiology are used to investigate risks for persistence of common pain syndromes (in this case, the low back) which present to primary care. Such studies have been set in a variety of countries and primary care disciplines. Many have been concerned with outcomes up to 1 year. The new study, although modest in size and based on patients recruited to a treatment trial, has follow-up of 5 years and adds new evidence about longer-term prognosis. There is consistency between the different studies and across different pain syndromes. Local injury and mechanical stress influence the onset of pain in a particular body location (Linaker et al., 1999) but appear less important in predicting chronicity. Predictors of chronicity are similar, regardless of pain location. Pain severity, extent of the accompanying disability, a previous disabling episode and overall course of the pain so far, and longer duration of the episode before it reaches primary care, all increase the likelihood that the problem will become persistent. Enthoven has confirmed that similar factors predict longer-term disability. Duration prior to consultation may simply be describing natural history – short sharp episodes destined to resolve quickly present earlier than slowly developing less dramatic problems destined to last longer – which introduces potential bias into prognostic studies if it is assumed that early consultation is having a beneficial effect on outcome. Such natural history may represent the ‘‘tracking’’ or trajectory of any one individual’s pain over a period of time or during the course of their life. This phenomenon, well known in cardiovascular epidemiology, means that patients on a particular track in a chronic illness tend to stick to it, and baseline severity and duration may simply be measuring the point the patient has reached on their track (see, for example, Von Korff and Miglioretti, 2005). There is little current evidence

Variation in Back Pain Between Countries: The Example of Britain and Germany

Study Design. Cross-sectional survey with personal interviews. Objective. To study national differences in subjective health, back pain, and self-perceived disability between the United Kingdom and Germany. Summary of Background Data. Back pain is a leading health problem in most Western populations, causing enormous costs to the national health systems. Different prevalence rates were reported from many countries, but rarely as a result of a direct comparison based on an identical study design. Methods. A total of 6,235 male and female participants 50 to 79 years of age (population-based stratified random samples) were recruited in 6 British and 8 German study centers. The interviewer administered standardized questionnaire included a section about presence and severity of back pain. Results. Past and current back pain was more frequent among German participants and different between East and West German centers. The differences in back pain prevalence rates could not be explained by less favorable risk profiles among German respondents. Conclusions. Intercultural differences in perceiving or reporting back pain can be hypothesized as the most likely explanation of the markedly different prevalence rates of the disorder in the United Kingdom and East and West Germany.

Does attrition bias longitudinal population-based studies on back pain?

Background and aims: Longitudinal population studies are a keystone in describing the course of back pain over time. Yet, potential bias because of repeated attrition has received little attention. This study aims to identify those back pain related indicators most susceptible to bias and to discuss practical consequences for back pain research.

Prävalenz der vertebralen Wirbelkörperdeformationen bei Frauen und Männern in Deutschland

BACKGROUND The prevalence of radiographically defined vertebral deformities, as a marker of vertebral osteoporosis, was calculated in a population based cross-sectional survey in Germany. METHOD Lateral spine X-rays were taken according to a standardized protocol and evaluated centrally. Three thousand nine hundred and eighty subjects (2064 male and 1916 female) aged 50 to 79 years, have been examined in 8 German centers. RESULTS Based on McCloskeys method of deformity definition the age-standardized mean prevalence of vertebral deformities in Germany was 10.2% for males and 10.5% for females. Based on the definition by Melton/Eastell a significant higher prevalence was calculated (males 17.8%, females 18.7%). The prevalence increased with age in both sexes with a steeper increase in females. There was no difference in East and West German populations. There were substantial variations between the centers regarding the prevalence of deformities in females and males.Summary□Background: The prevalence of radiographically defined vertebral deformities, as a marker of vertebral osteoporosis, was calculated in a population based cross-sectional survey in Germany.□Method: Lateral spine X-rays were taken according to a standardized protocol and evaluated centrally. Three thousand nine hundred and eighty subjects (2064 male and 1916 female) aged 50 to 79 years, have been examined in 8 German centers.□Results: Based on McCloskey’s method of deformity definition the age-standardized mean prevalence of vertebral deformities in Germany was 10.2% for males and 10.5% for females. Based on the definition by Melton/Eastell as significant higher prevalence was calculated (males 17.8%, females 18.7%). The prevalence increased with age in both sexes with a steeper increase in females. There was no difference in East and West German populations. There were substantial variations between the centers regarding the prevalence of deformities in females and males.

Epidemiologie der Osteoporose

Summary□ Epidemiological studies have identified osteoporosis as a disease of significant public health impact and have delineated numerous potential risk factors. Nevertheless, it has proven difficult to establish preventive strategies for several reasons. First, there has been no final agreement on the definition of osteoporosis, which has hampered efforts to characterize the magnitude of the problem as a whole. Secondly, as osteoporosis is a multifactorial chronic disorder, effective programs for risk assessment and intervention depend on the development of complex disease models. In summarizing the contributions of epidemiological studies to the current understanding of osteoporosis this review intends to outline the scientific background for the European Vertebral osteoporosis Study (EVOS) and its successors.

Die Reliabilität radiologischer Befunde zur Differentialdiagnose der vertebralen Osteoporose

Summary□Background: Radiologically identified vertebral deformities, e. g. wedge-, fish-, or crush-vertebrae are not always a consequence of local osteoporosis. Other frequent pathomechanisms include Morbus Scheuermann, degenerative changes, overt trauma, and congenital dysplasia. This requires differential diagnosis of vertebral deformities. Radiological classification criteria have to satisfy various methodological requirements to ensure reliability of the results.□Methods: Inter-rater reliability of more than 30 radiological findings was assessed in 4 German centres of the European Vertebral Osteoporosis Study (EVOS). One hundred randomly selected EVOS cases from the West-Berlin population, each contributing 2 lateral X-rays from the thoracic and lumbar spine respectively, were independently evaluated by 7 observers. All observers were medical doctors, 4 of them heads or members of clinical radiological departments. Thus each observer read 200 radiographs. Radiological alterations in the form and structure of 13 vertebrale which were considered to be relevant for the differential diagnosis of osteoporosis were recorded in a standardized documentation form. Additionally global judgements (e. g. “osteoporotic spine” yes/no) were required. To quantify agreement Fleiss’ kappa (κ) for nominal data and multiple observers was used.□Results: Only 4% of all vertebral columns were stated as “normal”, 25% as “osteoporotic”. This last figure exceeded more than 2-fold the prevalence of significant vertebral deformities, as based on semiautomatic morphometry (about 10%). Wedge deformities were found on average in 39% of all thoracic and 5% of all lumbar X-rays with ranges of 20% to 53% and 2% to 10% respectively among 7 observers. For both variables, agreement (κ) between the observers was below 0.40. The highest agreement was found for the assessment of fractures of the upper and/or lower lamina of lumbar vertebrae (κ=0.58). Agreement did not vary between radiologists and non-radiologists. Higher κ-values were recorded for observers working in the same centre (0.50 to 0.90).□Conclusion: There is an urgent need for the differential diagnosis of vertebral deformities which in half of all cases may be caused by vertebral osteoporosis. The low inter-rater reliability of 30 radiological characteristics seriously interferes with this task. Moderate to good agreement was seen only among observers coming from the same centre. It may be concluded that a more intensive training is likely to lead to better agreement. However, this is a time and resource consuming option. It may be equally appropriate to include further information from other sources such as bone mass measurement to identify osteoporosis related vertebral deformities. In the meantime, prevalence estimations and case control studies based solely on vertebral morphometry have to be interpreted with caution.

Die europäische Studie zur vertebralen Osteoporose (EVOS): Teilnahmebereitschaft und Selektionsverzerrung in Deutschland

Summary□Background: In population-based studies non-participation rates of about one third of the sample can be expected. The number of refusals may even be higher, if personal attendence of the subjects is requested. A different participation behaviour of the diseased and non-diseased may affect the prevalence estimation of a disease as well as the risk factor association.□Methods and Results: The European Vertebral Osteoporosis Study (EVOS) is an international, multicenter, cross-sectional survey in men and women aged 50 to 79 years. Within Europe 36 centres recruited 17 342 participants. The 8 German centres contribute about one fourth of the data. In Germany subjects were recruited in several steps: random sample drawing from population registries, initial postal questionnaire, medical interview, lateral X-rays of the thoracic and lumbar spine. Depending on the extent of participation a variable amount of sociodemographic data and information on subjective health is available from the non-reachable, non-responders, and responders with incomplete and with complete examination. A comparison of the different participation groups showed, that especially old women were lost from the study. Compared to those, who only answered to an initial questionaire, subjects, who were interviewed and X-rayed, more often suffered from back pain but reported a better functional capacity. This could be a hint on a selection of a population of the “worried well”.□Conclusions: On the whole the selection processes seem to have a minor influence on the outcome. The initial postal questionnaire turned out to be effective in collecting basic information from those who refused to attend a personal examination.

KRANKHEITSLAST BEI VERTEBRALEN DEFORMITATEN

Summary□Background: In the course of the European Vertebral Osteoprosis Study (EVOS) 4060 men and women (target age 50 to 79 years; age and sex-stratified random samples from official population registers) were examined according to the standardized study protocol in 8 German study centres.□Methods: The study programme comprised an intial postal health questionnaire, a medical interview concerning risk factors and health impact and lateral X-rays of the thoracic and the lumbar spine. Vertebral deformities were defined morphometrically. The association between prevalent deformities and subjective health impairments was investigated using 2 different morphometric classifications. The following variables were included as indicators of reduced health: back pain ever/within the last 12 months/currently, back pain intensity, functional capacity (ADL-list), graded back pain, subjective health, depression and grip strength.□Results: Bivariate analyses (gc2 test, t-Test) as well as logistic regression analysis revealed significant associations between vertebral deformities and several negative health outcomes (odds ratios between 0.75 and 4.65, depending on definition of deformity). The associations were stronger in women.BACKGROUND In the course of the European Vertebral Osteoporosis Study (EVOS) 4060 men and women (target age 50 to 79 years; age and sex-stratified random samples from official population registers) were examined according to the standardized study protocol in 8 German study centres. METHODS The study programme comprised an initial postal health questionnaire, a medical interview concerning risk factors and health impact and lateral X-rays of the thoracic and the lumbar spine. Vertebral deformities were defined morphometrically. The association between prevalent deformities and subjective health impairments was investigated using 2 different morphometric classifications. The following variables were included as indicators of reduced health: back pain ever/within the last 12 months/currently, back pain intensity, functional capacity (ADL-list), graded back pain, subjective health, depression and grip strength. RESULTS Bivariate analyses (chi(2) test, t-Test) as well as logistic regression analysis revealed significant associations between vertebral deformities and several negative health outcomes (odds ratios between 0.75 and 4.65, depending on definition of deformity). The associations were stronger in women.