The size and burden of mental disorders and other disorders of the brain in Europe 2010

AIMS

To provide 12-month prevalence and disability burden estimates of a broad range of mental and neurological disorders in the European Union (EU) and to compare these findings to previous estimates. Referring to our previous 2005 review, improved up-to-date data for the enlarged EU on a broader range of disorders than previously covered are needed for basic, clinical and public health research and policy decisions and to inform about the estimated number of persons affected in the EU.

METHOD

Stepwise multi-method approach, consisting of systematic literature reviews, reanalyses of existing data sets, national surveys and expert consultations. Studies and data from all member states of the European Union (EU-27) plus Switzerland, Iceland and Norway were included. Supplementary information about neurological disorders is provided, although methodological constraints prohibited the derivation of overall prevalence estimates for mental and neurological disorders. Disease burden was measured by disability adjusted life years (DALY).

RESULTS

Prevalence: It is estimated that each year 38.2% of the EU population suffers from a mental disorder. Adjusted for age and comorbidity, this corresponds to 164.8million persons affected. Compared to 2005 (27.4%) this higher estimate is entirely due to the inclusion of 14 new disorders also covering childhood/adolescence as well as the elderly. The estimated higher number of persons affected (2011: 165m vs. 2005: 82m) is due to coverage of childhood and old age populations, new disorders and of new EU membership states. The most frequent disorders are anxiety disorders (14.0%), insomnia (7.0%), major depression (6.9%), somatoform (6.3%), alcohol and drug dependence (>4%), ADHD (5%) in the young, and dementia (1-30%, depending on age). Except for substance use disorders and mental retardation, there were no substantial cultural or country variations. Although many sources, including national health insurance programs, reveal increases in sick leave, early retirement and treatment rates due to mental disorders, rates in the community have not increased with a few exceptions (i.e. dementia). There were also no consistent indications of improvements with regard to low treatment rates, delayed treatment provision and grossly inadequate treatment. Disability: Disorders of the brain and mental disorders in particular, contribute 26.6% of the total all cause burden, thus a greater proportion as compared to other regions of the world. The rank order of the most disabling diseases differs markedly by gender and age group; overall, the four most disabling single conditions were: depression, dementias, alcohol use disorders and stroke.

CONCLUSION

In every year over a third of the total EU population suffers from mental disorders. The true size of "disorders of the brain" including neurological disorders is even considerably larger. Disorders of the brain are the largest contributor to the all cause morbidity burden as measured by DALY in the EU. No indications for increasing overall rates of mental disorders were found nor of improved care and treatment since 2005; less than one third of all cases receive any treatment, suggesting a considerable level of unmet needs. We conclude that the true size and burden of disorders of the brain in the EU was significantly underestimated in the past. Concerted priority action is needed at all levels, including substantially increased funding for basic, clinical and public health research in order to identify better strategies for improved prevention and treatment for disorders of the brain as the core health challenge of the 21st century.

COSMIN guideline for systematic reviews of patient-reported outcome measures

Purpose

Systematic reviews of patient-reported outcome measures (PROMs) differ from reviews of interventions and diagnostic test accuracy studies and are complex. In fact, conducting a review of one or more PROMs comprises of multiple reviews (i.e., one review for each measurement property of each PROM). In the absence of guidance specifically designed for reviews on measurement properties, our aim was to develop a guideline for conducting systematic reviews of PROMs.

Methods

Based on literature reviews and expert opinions, and in concordance with existing guidelines, the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) steering committee developed a guideline for systematic reviews of PROMs.

Results

A consecutive ten-step procedure for conducting a systematic review of PROMs is proposed. Steps 1–4 concern preparing and performing the literature search, and selecting relevant studies. Steps 5–8 concern the evaluation of the quality of the eligible studies, the measurement properties, and the interpretability and feasibility aspects. Steps 9 and 10 concern formulating recommendations and reporting the systematic review.

Conclusions

The COSMIN guideline for systematic reviews of PROMs includes methodology to combine the methodological quality of studies on measurement properties with the quality of the PROM itself (i.e., its measurement properties). This enables reviewers to draw transparent conclusions and making evidence-based recommendations on the quality of PROMs, and supports the evidence-based selection of PROMs for use in research and in clinical practice.

COSMIN Risk of Bias checklist for systematic reviews of Patient-Reported Outcome Measures

PURPOSE

The original COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist was developed to assess the methodological quality of single studies on measurement properties of Patient-Reported Outcome Measures (PROMs). Now it is our aim to adapt the COSMIN checklist and its four-point rating system into a version exclusively for use in systematic reviews of PROMs, aiming to assess risk of bias of studies on measurement properties.

METHODS

For each standard (i.e., a design requirement or preferred statistical method), it was discussed within the COSMIN steering committee if and how it should be adapted. The adapted checklist was pilot-tested to strengthen content validity in a systematic review on the quality of PROMs for patients with hand osteoarthritis.

RESULTS

Most important changes were the reordering of the measurement properties to be assessed in a systematic review of PROMs; the deletion of standards that concerned reporting issues and standards that not necessarily lead to biased results; the integration of standards on general requirements for studies on item response theory with standards for specific measurement properties; the recommendation to the review team to specify hypotheses for construct validity and responsiveness in advance, and subsequently the removal of the standards about formulating hypotheses; and the change in the labels of the four-point rating system.

CONCLUSIONS

The COSMIN Risk of Bias checklist was developed exclusively for use in systematic reviews of PROMs to distinguish this application from other purposes of assessing the methodological quality of studies on measurement properties, such as guidance for designing or reporting a study on the measurement properties.

COSMIN methodology for evaluating the content validity of patient-reported outcome measures: a Delphi study

BACKGROUND

Content validity is the most important measurement property of a patient-reported outcome measure (PROM) and the most challenging to assess. Our aims were to: (1) develop standards for evaluating the quality of PROM development; (2) update the original COSMIN standards for assessing the quality of content validity studies of PROMs; (3) develop criteria for what constitutes good content validity of PROMs, and (4) develop a rating system for summarizing the evidence on a PROM's content validity and grading the quality of the evidence in systematic reviews of PROMs.

METHODS

An online 4-round Delphi study was performed among 159 experts from 21 countries. Panelists rated the degree to which they (dis)agreed to proposed standards, criteria, and rating issues on 5-point rating scales ('strongly disagree' to 'strongly agree'), and provided arguments for their ratings.

RESULTS

Discussion focused on sample size requirements, recording and field notes, transcribing cognitive interviews, and data coding. After four rounds, the required 67% consensus was reached on all standards, criteria, and rating issues. After pilot-testing, the steering committee made some final changes. Ten criteria for good content validity were defined regarding item relevance, appropriateness of response options and recall period, comprehensiveness, and comprehensibility of the PROM.

DISCUSSION

The consensus-based COSMIN methodology for content validity is more detailed, standardized, and transparent than earlier published guidelines, including the previous COSMIN standards. This methodology can contribute to the selection and use of high-quality PROMs in research and clinical practice.

Cross-national prevalence and correlates of adult attention-deficit hyperactivity disorder

BACKGROUND

Little is known about the epidemiology of adult attention-deficit hyperactivity disorder (ADHD).

AIMS

To estimate the prevalence and correlates of DSM-IV adult ADHD in the World Health Organization World Mental Health Survey Initiative.

METHOD

An ADHD screen was administered to respondents aged 18-44 years in ten countries in the Americas, Europe and the Middle East (n=11422). Masked clinical reappraisal interviews were administered to 154 US respondents to calibrate the screen. Multiple imputation was used to estimate prevalence and correlates based on the assumption of cross-national calibration comparability.

RESULTS

Estimates of ADHD prevalence averaged 3.4% (range 1.2-7.3%), with lower prevalence in lower-income countries (1.9%) compared with higher-income countries (4.2%). Adult ADHD often co-occurs with other DSM-IV disorders and is associated with considerable role disability. Few cases are treated for ADHD, but in many cases treatment is given for comorbid disorders.

CONCLUSIONS

Adult ADHD should be considered more seriously in future epidemiological and clinical studies than is currently the case.

Translating health status questionnaires and evaluating their quality: the IQOLA Project approach. International Quality of Life Assessment

This article describes the methods adopted by the International Quality of Life Assessment (IQOLA) project to translate the SF-36 Health Survey. Translation methods included the production of forward and backward translations, use of difficulty and quality ratings, pilot testing, and cross-cultural comparison of the translation work. Experience to date suggests that the SF-36 can be adapted for use in other countries with relatively minor changes to the content of the form, providing support for the use of these translations in multinational clinical trials and other studies. The most difficult items to translate were physical functioning items, which used examples of activities and distances that are not common outside of the United States; items that used colloquial expressions such as pep or blue; and the social functioning items. Quality ratings were uniformly high across countries. While the IQOLA approach to translation and validation was developed for use with the SF-36, it is applicable to other translation efforts.

Prevalence of mental disorders in Europe: results from the European Study of the Epidemiology of Mental Disorders (ESEMeD) project

OBJECTIVE

To describe the 12-month and lifetime prevalence rates of mood, anxiety and alcohol disorders in six European countries.

METHOD

A representative random sample of non-institutionalized inhabitants from Belgium, France, Germany, Italy, the Netherlands and Spain aged 18 or older (n = 21425) were interviewed between January 2001 and August 2003. DSM-IV disorders were assessed by lay interviewers using a revised version of the Composite International Diagnostic Interview (WMH-CIDI).

RESULTS

Fourteen per cent reported a lifetime history of any mood disorder, 13.6% any anxiety disorder and 5.2% a lifetime history of any alcohol disorder. More than 6% reported any anxiety disorder, 4.2% any mood disorder, and 1.0% any alcohol disorder in the last year. Major depression and specific phobia were the most common single mental disorders. Women were twice as likely to suffer 12-month mood and anxiety disorders as men, while men were more likely to suffer alcohol abuse disorders.

CONCLUSION

ESEMeD is the first study to highlight the magnitude of mental disorders in the six European countries studied. Mental disorders were frequent, more common in female, unemployed, disabled persons, or persons who were never married or previously married. Younger persons were also more likely to have mental disorders, indicating an early age of onset for mood, anxiety and alcohol disorders.

The impact of measuring patient-reported outcomes in clinical practice: a systematic review of the literature

OBJECTIVE

The purpose of this paper is to summarize the best evidence regarding the impact of providing patient-reported outcomes (PRO) information to health care professionals in daily clinical practice.

METHODS

Systematic review of randomized clinical trials (Medline, Cochrane Library; reference lists of previous systematic reviews; and requests to authors and experts in the field).

RESULTS

Out of 1,861 identified references published between 1978 and 2007, 34 articles corresponding to 28 original studies proved eligible. Most trials (19) were conducted in primary care settings performed in the USA (21) and assessed adult patients (25). Information provided to professionals included generic health status (10), mental health (14), and other (6). Most studies suffered from methodologic limitations, including analysis that did not correspond with the unit of allocation. In most trials, the impact of PRO was limited. Fifteen of 23 studies (65%) measuring process of care observed at least one significant result favoring the intervention, as did eight of 17 (47%) that measured outcomes of care.

CONCLUSIONS

Methodological concerns limit the strength of inference regarding the impact of providing PRO information to clinicians. Results suggest great heterogeneity of impact; contexts and interventions that will yield important benefits remain to be clearly defined.

The Clinical Global Impression-Schizophrenia scale: a simple instrument to measure the diversity of symptoms present in schizophrenia

OBJECTIVE

To describe the development and validation of the Clinical Global Impression-Schizophrenia (CGI-SCH) scale, designed to assess positive, negative, depressive and cognitive symptoms in schizophrenia.

METHOD

The CGI-SCH scale was adapted from the CGI scale. Concurrent validity and sensitivity to change were assessed by comparison with the Positive and Negative Symptom Severity (PANSS) and Global Assessment of Functioning (GAF) scales. To evaluate inter-rater reliability, all patients were assessed by two clinicians.

RESULTS

Symptoms were assessed in 114 patients. Correlation coefficients between the CGI-SCH and the GAF and PANSS scores were high (most above 0.75), and were highest for positive and negative symptoms. Reliability was substantial (intraclass correlation coefficient, ICC > 0.70) in all but one dimension (depressive dimension, ICC = 0.64).

CONCLUSION

The CGI-SCH scale is a valid, reliable instrument to evaluate severity and treatment response in schizophrenia. Given its simplicity, brevity and clinical face validity, the scale is appropriate for use in observational studies and routine clinical practice.

Trp-dependent auxin biosynthesis in Arabidopsis: involvement of cytochrome P450s CYP79B2 and CYP79B3

The plant hormone auxin regulates many aspects of plant growth and development. Although several auxin biosynthetic pathways have been proposed, none of these pathways has been precisely defined at the molecular level. Here we provide in planta evidence that the two Arabidopsis cytochrome P450s, CYP79B2 and CYP79B3, which convert tryptophan (Trp) to indole-3-acetaldoxime (IAOx) in vitro, are critical enzymes in auxin biosynthesis in vivo. IAOx is thus implicated as an important intermediate in auxin biosynthesis. Plants overexpressing CYP79B2 contain elevated levels of free auxin and display auxin overproduction phenotypes. Conversely, cyp79B2 cyp79B3 double mutants have reduced levels of IAA and show growth defects consistent with partial auxin deficiency. Together with previous work on YUCCA, a flavin monooxygenase also implicated in IAOx production, and nitrilases that convert indole-3-acetonitrile to auxin, this work provides a framework for further dissecting auxin biosynthetic pathways and their regulation.

Evaluating quality-of-life and health status instruments: development of scientific review criteria

The Medical Outcomes Trust is a depository and distributor of high-quality, standardized, health outcomes measurement instruments to national and international health communities. Every instrument in the Trust library is reviewed by the Scientific Advisory Committee against a rigorous set of eight attributes. These attributes consist of the following: (1) conceptual and measurement model; (2) reliability; (3) validity; (4) responsiveness; (5) interpretability; (6) respondent and administrative burden; (7) alternative forms; and (8) cultural and language adaptations. In addition to a full description of each attribute, we discuss uses of these criteria beyond evaluation of existing instruments and lessons learned in the first few rounds of instrument review against these criteria.

International Quality of Life Assessment (IQOLA) Project

The International Quality of Life Assessment (IQOLA) Project is a 4-year project to translate and adapt the widely used MOS SF-36 Health Survey Questionnaire in up to 15 countries and validate, norm, and document the new translations as required for their use in international studies of health outcomes. In addition to the eight-scale SF-36 health profile, the project will also validate psychometrically based physical and mental health summary scores, as well as health utility indexes incorporating SF-36 scales for use in cost-utility studies.

Risk factors for suicidality in Europe: results from the ESEMED study

BACKGROUND

Precise knowledge of the epidemiology of suicidality provides necessary information for designing prevention programs. The aims of the present study were to investigate the prevalence and correlates of suicidal ideas and attempts in the general population of Europe.

METHODS

The European Study on the Epidemiology of Mental Disorders (ESEMED) is a cross-sectional household survey carried out in a probability representative sample of non-institutionalised adults (aged 18 years or older) of six European countries (Belgium, France, Germany, Italy, the Netherlands and Spain). The Composite International Diagnostic Interview (CIDI 3.0) was administered to 21,425 individuals.

RESULTS

Lifetime prevalence of suicidal ideation was 7.8% and of suicidal attempts 1.3%. Being women, younger and divorced or widowed were associated with a higher prevalence of suicide ideation and attempts. Psychiatric diagnoses were strongly related to suicidality. Among them, major depressive episode (Rate ratio 2.9 for lifetime ideas and 4.8 for lifetime attempts), dysthymia (RR 2.0 and 1.6), GAD (RR 1.8 and 2.3 for lifetime), PTSD (RR 1.9 and 2.0) and alcohol dependence (RR 1.7 and 2.5) were the most important. Population attributable risks for lifetime suicidal attempt was 28% for major depression.

LIMITATIONS

Information about suicidal ideas and attempts was self reported, psychiatric diagnoses were made using fully structured lay interviews rather than clinician-administered interviews.

CONCLUSIONS

In spite of meaningful country variation in prevalence, risk factors for suicidality are consistent in the European countries. Population prevention programmes should focus on early diagnosis and treatment of major depression and alcohol abuse and in those individuals with recent appearance of suicidal ideas.

Depression-anxiety relationships with chronic physical conditions: results from the World Mental Health Surveys

BACKGROUND

Prior research on the association between affective disorders and physical conditions has been carried out in developed countries, usually in clinical populations, on a limited range of mental disorders and physical conditions, and has seldom taken into account the comorbidity between depressive and anxiety disorders.

METHODS

Eighteen general population surveys were carried out among adults in 17 countries as part of the World Mental Health Surveys initiative (N=42, 249). DSM-IV depressive and anxiety disorders were assessed using face-to-face interviews with the Composite International Diagnostic Interview (CIDI 3.0). Chronic physical conditions were ascertained via a standard checklist. The relationship between mental disorders and physical conditions was assessed by considering depressive and anxiety disorders independently (depression without anxiety; anxiety without depression) and conjointly (depression plus anxiety).

RESULTS

All physical conditions were significantly associated with depressive and/or anxiety disorders but there was variation in the strength of association (ORs 1.2-4.5). Non-comorbid depressive and anxiety disorders were associated in equal degree with physical conditions. Comorbid depressive-anxiety disorder was more strongly associated with several physical conditions than were single mental disorders.

LIMITATIONS

Physical conditions were ascertained via self report, though for a number of conditions this was self-report of diagnosis by a physician.

CONCLUSIONS

Given the prevalence and clinical consequences of the co-occurrence of mental and physical disorders, attention to their comorbidity should remain a clinical and research priority.

Days out of role due to common physical and mental conditions: results from the WHO World Mental Health surveys

Days out of role because of health problems are a major source of lost human capital. We examined the relative importance of commonly occurring physical and mental disorders in accounting for days out of role in 24 countries that participated in the World Health Organization (WHO) World Mental Health (WMH) surveys. Face-to-face interviews were carried out with 62 971 respondents (72.0% pooled response rate). Presence of ten chronic physical disorders and nine mental disorders was assessed for each respondent along with information about the number of days in the past month each respondent reported being totally unable to work or carry out their other normal daily activities because of problems with either physical or mental health. Multiple regression analysis was used to estimate associations of specific conditions and comorbidities with days out of role, controlling by basic socio-demographics (age, gender, employment status and country). Overall, 12.8% of respondents had some day totally out of role, with a median of 51.1 a year. The strongest individual-level effects (days out of role per year) were associated with neurological disorders (17.4), bipolar disorder (17.3) and post-traumatic stress disorder (15.2). The strongest population-level effect was associated with pain conditions, which accounted for 21.5% of all days out of role (population attributable risk proportion). The 19 conditions accounted for 62.2% of all days out of role. Common health conditions, including mental disorders, make up a large proportion of the number of days out of role across a wide range of countries and should be addressed to substantially increase overall productivity.

Tests of data quality, scaling assumptions, and reliability of the SF-36 in eleven countries: results from the IQOLA Project. International Quality of Life Assessment

Data from general population samples in 11 countries (n = 1483 to 9151) were used to assess data quality and test the assumptions underlying the construction and scoring of multi-item scales from the SF-36 Health Survey. Across all countries, the rate of item-level missing data generally was low, although slightly higher for items printed in the grid format. In each country, item means generally were clustered as hypothesized within scales. Correlations between items and hypothesized scales were greater than 0.40 with one exception, supporting item internal consistency. Items generally correlated significantly higher with their own scale than with competing scales, supporting item discriminant validity. Scales could be constructed for 93-100% of respondents. Internal consistency reliability of the eight SF-36 scales was above 0.70 for all scales, with two exceptions. Floor effects were low for all except the two role functioning scales; ceiling effects were high for both role functioning scales and also were noteworthy for the Physical Functioning, Bodily Pain, and Social Functioning scales in some countries. These results support the construction and scoring of the SF-36 translations in these 11 countries using the method of summated ratings.

Obesity and mental disorders in the general population: results from the world mental health surveys

OBJECTIVES

(1) To investigate whether there is an association between obesity and mental disorders in the general populations of diverse countries, and (2) to establish whether demographic variables (sex, age, education) moderate any associations observed.

DESIGN

Thirteen cross-sectional, general population surveys conducted as part of the World Mental Health Surveys initiative.

SUBJECTS

Household residing adults, 18 years and over (n=62 277).

MEASUREMENTS

DSM-IV mental disorders (anxiety disorders, depressive disorders, alcohol use disorders) were assessed with the Composite International Diagnostic Interview (CIDI 3.0), a fully structured diagnostic interview. Obesity was defined as a body mass index (BMI) of 30 kg/m(2) or greater; severe obesity as BMI 35+. Persons with BMI less than 18.5 were excluded from analysis. Height and weight were self-reported.

RESULTS

Statistically significant, albeit modest associations (odds ratios generally in the range of 1.2-1.5) were observed between obesity and depressive disorders, and between obesity and anxiety disorders, in pooled data across countries. These associations were concentrated among those with severe obesity, and among females. Age and education had variable effects across depressive and anxiety disorders.

CONCLUSIONS

The findings are suggestive of a modest relationship between obesity (particularly severe obesity) and emotional disorders among women in the general population. The study is limited by the self-report of BMI and cannot clarify the direction or nature of the relationship observed, but it may indicate a need for a research and clinical focus on the psychological heterogeneity of the obese population.

COSMIN Risk of Bias tool to assess the quality of studies on reliability or measurement error of outcome measurement instruments: a Delphi study

BACKGROUND

Scores on an outcome measurement instrument depend on the type and settings of the instrument used, how instructions are given to patients, how professionals administer and score the instrument, etc. The impact of all these sources of variation on scores can be assessed in studies on reliability and measurement error, if properly designed and analyzed. The aim of this study was to develop standards to assess the quality of studies on reliability and measurement error of clinician-reported outcome measurement instruments, performance-based outcome measurement instrument, and laboratory values.

METHODS

We conducted a 3-round Delphi study involving 52 panelists.

RESULTS

Consensus was reached on how a comprehensive research question can be deduced from the design of a reliability study to determine how the results of a study inform us about the quality of the outcome measurement instrument at issue. Consensus was reached on components of outcome measurement instruments, i.e. the potential sources of variation. Next, we reached consensus on standards on design requirements (n = 5), standards on preferred statistical methods for reliability (n = 3) and measurement error (n = 2), and their ratings on a four-point scale. There was one term for a component and one rating of one standard on which no consensus was reached, and therefore required a decision by the steering committee.

CONCLUSION

We developed a tool that enables researchers with and without thorough knowledge on measurement properties to assess the quality of a study on reliability and measurement error of outcome measurement instruments.

Validity and reliability of the St George's Respiratory Questionnaire after adaptation to a different language and culture: the Spanish example

We describe the adaptation into Spanish of the St George's Respiratory Questionnaire (SGRQ), a self-administered questionnaire developed by Jones et al. (1991) covering three domains of health in airways disease patients: symptoms, activity and impacts. For the adaptation, the forward and back-translation method by bilinguals was used, together with professional committee and lay panel. Once tested for feasibility and comprehension, 318 male chronic obstructive pulmonary disease (COPD) patients with a wide range of disease severity completed the Spanish version of the SGRQ. The clinical status of the patients was evaluated concurrently with the measurement of health status. Lung function was assessed in the 2 months before or after the questionnaire administration. The Spanish version of the SGRQ was acceptable and easy to understand. Cronbach's alpha reliability coefficient was 0.94 for the overall scale and 0.72 for "Symptoms", 0.89 for "Activity", and 0.89 for "Impacts" subscales. Correlation coefficients between the overall score and dyspnoea and % forced expiratory volume in one second (FEV1) were 0.59 and -0.45, respectively, and these correlations were higher than those observed between the clinical variables and the Nottingham Health Profile, a generic measure of health-related quality of life. Results of the study suggest that the Spanish version of the SGRQ is conceptually equivalent to the original, and similarly reliable and valid. Although further studies should complete the adaptation work, results suggest that the SGRQ may already be used in Spain and in international studies involving Spanish respiratory patients. According to the present approach, it appears to be feasible to adapt a specific questionnaire on health-related quality of life in respiratory disease to another language and culture.

Chronic obstructive pulmonary disease stage and health-related quality of life. The Quality of Life of Chronic Obstructive Pulmonary Disease Study Group

BACKGROUND

The American Thoracic Society recently recommended that chronic obstructive pulmonary disease be staged on the basis of the percentage of predicted FEV1.

OBJECTIVE

To examine 1) the relation between the american Thoracic Society system for staging chronic obstructive pulmonary disease and health-related quality of life and 2) the effect of self-reported comorbid conditions on health-related quality of life.

DESIGN

Cross-sectional study.

SETTING

Outpatient clinics of respiratory departments of four hospitals and one primary health care center in spain.

PATIENTS

321 consecutive male patients with chronic obstructive pulmonary disease.

MEASUREMENTS

Functional respiratory impairment, FEV1, respiratory symptoms, and health-related quality of life. Respiratory symptoms and health-related quality of life were measured by using the Spanish version of the St. George's Respiratory Questionnaire and the Nottingham Health Profile.

RESULTS

Patient scores on the St. George's Respiratory Questionnaire were moderately to strongly associated with disease staging (r = 0.27 to 0.51). Compared with reference values, values for health-related quality of life for patients with stage I disease were substantially higher on the St. George's Respiratory Questionnaire (6 and 34; p < 0.001) and values for impairment were significantly greater in stage 1 patients with comorbid conditions (19 and 36; P = 0.001). At least one concomitant chronic condition was found in 84% of study patients. Comorbid conditions only partly influenced the observed pattern of deterioration of health-related quality of life with worsening stages of disease.

CONCLUSION

Staging criteria for chronic obstructive pulmonary disease based on percentage of predicted FEV1 separated groups of patients with varying degrees of impairment in health-related quality of life. Contrary to expectations, even patients with mild disease showed substantially compromised health-related quality of life. Comorbid conditions influenced the relation between chronic obstructive pulmonary disease and health-related quality of life.

MR imaging findings in hepatic encephalopathy

The term hepatic encephalopathy (HE) includes a spectrum of neuropsychiatric abnormalities occurring in patients with liver dysfunction. Most cases are associated with cirrhosis and portal hypertension or portal-systemic shunts, but the condition can also be seen in patients with acute liver failure and, rarely, with portal-systemic bypass and no associated intrinsic hepatocellular disease. Although HE is a clinical condition, several neuroimaging techniques, particularly MR imaging, may eventually be useful for the diagnosis because they can identify and measure the consequences of central nervous system (CNS) increase in substances that under normal circumstances, are efficiently metabolized by the liver. Classic MR imaging abnormalities include high signal intensity in the globus pallidum on T1-weighted images, likely a reflection of increased tissue concentrations of manganese, and an elevated glutamine/glutamate peak coupled with decreased myo-inositol and choline signals on proton MR spectroscopy, representing disturbances in cell-volume homeostasis secondary to brain hyperammonemia. Recent data have shown that white matter abnormalities, also related to increased CNS ammonia concentration, can also be detected with several MR imaging techniques such as magnetization transfer ratio measurements, fast fluid-attenuated inversion recovery sequences, and diffusion-weighted images. All these MR imaging abnormalities, which return to normal with restoration of liver function, probably reflect the presence of mild diffuse brain edema, which seems to play an essential role in the pathogenesis of HE. It is likely that MR imaging will be increasingly used to evaluate the mechanisms involved in the pathogenesis of HE and to assess the effects of therapeutic measures focused on correcting brain edema in these patients.

Protocol of the COSMIN study: COnsensus-based Standards for the selection of health Measurement INstruments

BACKGROUND

Choosing an adequate measurement instrument depends on the proposed use of the instrument, the concept to be measured, the measurement properties (e.g. internal consistency, reproducibility, content and construct validity, responsiveness, and interpretability), the requirements, the burden for subjects, and costs of the available instruments. As far as measurement properties are concerned, there are no sufficiently specific standards for the evaluation of measurement properties of instruments to measure health status, and also no explicit criteria for what constitutes good measurement properties. In this paper we describe the protocol for the COSMIN study, the objective of which is to develop a checklist that contains COnsensus-based Standards for the selection of health Measurement INstruments, including explicit criteria for satisfying these standards. We will focus on evaluative health related patient-reported outcomes (HR-PROs), i.e. patient-reported health measurement instruments used in a longitudinal design as an outcome measure, excluding health care related PROs, such as satisfaction with care or adherence. The COSMIN standards will be made available in the form of an easily applicable checklist.

METHOD

An international Delphi study will be performed to reach consensus on which and how measurement properties should be assessed, and on criteria for good measurement properties. Two sources of input will be used for the Delphi study: (1) a systematic review of properties, standards and criteria of measurement properties found in systematic reviews of measurement instruments, and (2) an additional literature search of methodological articles presenting a comprehensive checklist of standards and criteria. The Delphi study will consist of four (written) Delphi rounds, with approximately 30 expert panel members with different backgrounds in clinical medicine, biostatistics, psychology, and epidemiology. The final checklist will subsequently be field-tested by assessing the inter-rater reproducibility of the checklist.

DISCUSSION

Since the study will mainly be anonymous, problems that are commonly encountered in face-to-face group meetings, such as the dominance of certain persons in the communication process, will be avoided. By performing a Delphi study and involving many experts, the likelihood that the checklist will have sufficient credibility to be accepted and implemented will increase.

Cross-cultural adaptation of health measures. European Group for Health Management and Quality of Life Assessment

There is increasing interest throughout Europe in measuring health needs in the general population and in the 'quality of life' of patients. This has led to a demand for questionnaires capable of measuring health status in a reliable and valid manner. Most existing measures have, however, been standardised only in the U.S.A. and, to a lesser extent, in the U.K. The issue of translation and retesting of questionnaires prepared in the English language for use in other countries has received surprisingly little attention. This paper describes some of the technical, linguistic and conceptual issues raised by translation and the processes involved in producing acceptable country-specific versions of the Nottingham Health Profile according to a systematic method.

Disability and quality of life impact of mental disorders in Europe: results from the European Study of the Epidemiology of Mental Disorders (ESEMeD) project

OBJECTIVE

This manuscript examines the impact of mental health state and specific mental and physical disorders on work role disability and quality of life in six European countries.

METHOD

The ESEMeD study was conducted in: Belgium, France, Germany, Italy, the Netherlands and Spain. Individuals aged 18 years and over who were not institutionalized were eligible for an in-home computer-assisted interview. Common mental disorders, work loss days (WLD) in the past month and quality of life (QoL) were assessed, using the WMH-2000 version of the CIDI, the WHODAS-II, and the mental and physical component scores (MCS, PCS) of the 12-item short form, respectively. The presence of five chronic physical disorders: arthritis, heart disease, lung disease, diabetes and neurological disease was also assessed. Multivariate regression techniques were used to identify the independent association of mental and physical disorders while controlling for gender, age and country.

RESULTS

In each country, WLD and loss of QoL increased with the number of disorders. Most mental disorders had approximately 1.0 SD-unit lower mean MCS and lost three to four times more work days, compared with people without any 12-month mental disorder. The 10 disorders with the highest independent impact on WLD were: neurological disease, panic disorder, PTSD, major depressive episode, dysthymia, specific phobia, social phobia, arthritis, agoraphobia and heart disease. The impact of mental vs. physical disorders on QoL was specific, with mental disorders impacting more on MCS and physical disorders more on PCS. Compared to physical disorders, mental disorders had generally stronger 'cross-domain' effects.

CONCLUSION

The results suggest that mental disorders are important determinants of work role disability and quality of life, often outnumbering the impact of common chronic physical disorders.