Somnath Chatterji

Depression, chronic diseases, and decrements in health: results from the World Health Surveys

BACKGROUND Depression is an important public-health problem, and one of the leading causes of disease burden worldwide. Depression is often comorbid with other chronic diseases and can worsen their associated health outcomes. Few studies have explored the effect of depression, alone or as a comorbidity, on overall health status. METHODS The WHO World Health Survey (WHS) studied adults aged 18 years and older to obtain data for health, health-related outcomes, and their determinants. Prevalence of depression in respondents based on ICD-10 criteria was estimated. Prevalence values for four chronic physical diseases--angina, arthritis, asthma, and diabetes--were also estimated using algorithms derived via a Diagnostic Item Probability Study. Mean health scores were constructed using factor analysis and compared across different disease states and demographic variables. The relation of these disease states to mean health scores was determined through regression modelling. FINDINGS Observations were available for 245 404 participants from 60 countries in all regions of the world. Overall, 1-year prevalence for ICD-10 depressive episode alone was 3.2% (95% CI 3.0-3.5); for angina 4.5% (4.3-4.8); for arthritis 4.1% (3.8-4.3); for asthma 3.3% (2.9-3.6); and for diabetes 2.0% (1.8-2.2). An average of between 9.3% and 23.0% of participants with one or more chronic physical disease had comorbid depression. This result was significantly higher than the likelihood of having depression in the absence of a chronic physical disease (p<0.0001). After adjustment for socioeconomic factors and health conditions, depression had the largest effect on worsening mean health scores compared with the other chronic conditions. Consistently across countries and different demographic characteristics, respondents with depression comorbid with one or more chronic diseases had the worst health scores of all the disease states. INTERPRETATION Depression produces the greatest decrement in health compared with the chronic diseases angina, arthritis, asthma, and diabetes. The comorbid state of depression incrementally worsens health compared with depression alone, with any of the chronic diseases alone, and with any combination of chronic diseases without depression. These results indicate the urgency of addressing depression as a public-health priority to reduce disease burden and disability, and to improve the overall health of populations.

ICF linking rules : an update based on lessons learned

OBJECTIVE Outcome research seeks to understand the end results of health services. Researchers use a wide variety of outcome measures including technical, clinical and patient-oriented measures. The International Classification of Functioning, Disability and Health (ICF) as a common reference framework for functioning may contribute to improved outcome research. The objective of this paper is to provide an updated version of the linking rules published in 2002 and illustrate how these rules are applied to link technical and clinical measures, health-status measures and interventions to the ICF. RESULTS Three specific linking rules have been established to link health-status measures to the ICF and one specific linking rule has been created to link technical and clinical measures and interventions. A total of 8 linking rules have been established for use with all different outcome measures and with interventions. CONCLUSION The newly updated linking rules will allow researchers systematically to link and compare meaningful concepts contained in them. This should prove extremely useful in selecting the most appropriate outcome measures among a number of candidate measures for the applied interventions. Further possible applications are the operationalization of concrete ICF categories using specific measures or the creation of ICF category-based item bankings.

Childhood adversities and adult psychopathology in the WHO World Mental Health Surveys

BACKGROUND Although significant associations of childhood adversities with adult mental disorders are widely documented, most studies focus on single childhood adversities predicting single disorders. AIMS To examine joint associations of 12 childhood adversities with first onset of 20 DSM-IV disorders in World Mental Health (WMH) Surveys in 21 countries. METHOD Nationally or regionally representative surveys of 51 945 adults assessed childhood adversities and lifetime DSM-IV disorders with the WHO Composite International Diagnostic Interview (CIDI). RESULTS Childhood adversities were highly prevalent and interrelated. Childhood adversities associated with maladaptive family functioning (e.g. parental mental illness, child abuse, neglect) were the strongest predictors of disorders. Co-occurring childhood adversities associated with maladaptive family functioning had significant subadditive predictive associations and little specificity across disorders. Childhood adversities account for 29.8% of all disorders across countries. CONCLUSIONS Childhood adversities have strong associations with all classes of disorders at all life-course stages in all groups of WMH countries. Long-term associations imply the existence of as-yet undetermined mediators.

The global burden of mental disorders: An update from the WHO World Mental Health (WMH) Surveys

AIMS The paper reviews recent findings from the WHO World Mental Health (WMH) surveys on the global burden of mental disorders. METHODS The WMH surveys are representative community surveys in 28 countries throughout the world aimed at providing information to mental health policy makers about the prevalence, distribution, burden, and unmet need for treatment of common mental disorders. RESULTS The first 17 WMH surveys show that mental disorders are commonly occurring in all participating countries. The inter-quartile range (IQR: 25th-75th percentiles) of lifetime DSM-IV disorder prevalence estimates (combining anxiety, mood, externalizing, and substance use disorders) is 18.1-36.1%. The IQR of 12-month prevalence estimates is 9.8-19.1%. Prevalence estimates of 12-month Serious Mental Illness (SMI) are 4-6.8% in half the countries, 2.3-3.6% in one-fourth, and 0.8-1.9% in one-fourth. Many mental disorders begin in childhood-adolescence and have significant adverse effects on subsequent role transitions in the WMH data. Adult mental disorders are found to be associated with such high role impairment in the WMH data that available clinical interventions could have positive cost-effectiveness ratios. CONCLUSIONS Mental disorders are commonly occurring and often seriously impairing in many countries throughout the world. Expansion of treatment could be cost-effective from both employer and societal perspectives.

Linking health-status measurements to the International Classification of Functioning, Disability and Health

With the approval of the International Classification of Functioning, Disability and Health by the World Health Assembly in May 2001, the concurrent use of both health-status measures and the International Classification of Functioning, Disability and Health is expected. It is therefore important to understand the relationship between these two concepts. The objective of this paper is to provide a systematic and standardized approach when linking health-status measures to the International Classification of Functioning, Disability and Health. The specific aims are to develop rules, to test their reliability and to illustrate these rules with examples. Ten linking rules and an example of their use are presented in this paper. The percentage agreement between two health professionals for 8 health-status instruments tested is also presented. A high level of agreement between the health professionals reflects that the linking rules established in this study allow the sound linking of items from health-status measures to the International Classification of Functioning, Disability and Health.

Development of ICF Core Sets for patients with chronic conditions

OBJECTIVE The objective of the ICF Core Sets project is the development of internationally agreed Brief ICF Core Sets and Comprehensive ICF Core Sets. METHODS The methods to develop both ICF Core Sets, the Comprehensive ICF Core Set and the Brief ICF Core Set, involved a formal decision-making and consensus process integrating evidence gathered from preliminary studies and expert opinion. RESULTS The results regarding the development of the ICF Core Sets for 12 health conditions (chronic widespread pain, low back pain, osteoarthritis, osteoporosis, rheumatoid arthritis, chronic ischemic heart disease, diabetes mellitus, obesity, obstructive pulmonary diseases, breast cancer, depression, and stroke) are presented in this supplement. CONCLUSION Both, the Brief ICF Core Sets and the Comprehensive ICF Core Sets are preliminary and need to be tested in the coming years based on a standardized protocol in close cooperation with the ICF research branch of the WHO FIC CC (DIMDI) in Munich and the CAS team at WHO. The final goals are valid and globally agreed tools to be used in clinical practice, research and health statistics.

Searching for an Operational Definition of Frailty: A Delphi Method Based Consensus Statement. The Frailty Operative Definition-Consensus Conference Project

BACKGROUND There is no consensus regarding the definition of frailty for clinical uses. METHODS A modified Delphi process was used to attempt to achieve consensus definition. Experts were selected from different fields and organized into five Focus Groups. A questionnaire was developed and sent to experts in the area of frailty. Responses and comments were analyzed using a pre-established strategy. Statements with an agreement more than or equal to 80% were accepted. RESULTS Overall, 44% of the statements regarding the concept of frailty and 18% of the statements regarding diagnostic criteria were accepted. There was consensus on the value of screening for frailty and about the identification of six domains of frailty for inclusion in a clinical definition, but no agreement was reached concerning a specific set of clinical/laboratory biomarkers useful for diagnosis. CONCLUSIONS There is agreement on the usefulness of defining frailty in clinical settings as well as on its main dimensions. However, additional research is needed before an operative definition of frailty can be established.

Developing the World Health Organization Disability Assessment Schedule 2.0

OBJECTIVE To describe the development of the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) for measuring functioning and disability in accordance with the International Classification of Functioning, Disability and Health. WHODAS 2.0 is a standard metric for ensuring scientific comparability across different populations. METHODS A series of studies was carried out globally. Over 65,000 respondents drawn from the general population and from specific patient populations were interviewed by trained interviewers who applied the WHODAS 2.0 (with 36 items in its full version and 12 items in a shortened version). FINDINGS The WHODAS 2.0 was found to have high internal consistency (Cronbachs alpha, α: 0.86), a stable factor structure; high test-retest reliability (intraclass correlation coefficient: 0.98); good concurrent validity in patient classification when compared with other recognized disability measurement instruments; conformity to Rasch scaling properties across populations, and good responsiveness (i.e. sensitivity to change). Effect sizes ranged from 0.44 to 1.38 for different health interventions targeting various health conditions. CONCLUSION The WHODAS 2.0 meets the need for a robust instrument that can be easily administered to measure the impact of health conditions, monitor the effectiveness of interventions and estimate the burden of both mental and physical disorders across different populations.

The International Classification of Functioning, Disability and Health: a new tool for understanding disability and health

Reliable and timely information about the health of populations is part of the World Health Organizations mandate in the development of international public health policy. To capture data concerning functioning and disability, or non-fatal health outcomes, WHO has recently published the revised International Classification of Functioning, Disability and Health (ICF). In this article, the authors briefly outline the revision process and discuss the rationale for the ICF and the needs that it serves in rehabilitation. The ICF is shown to be an essential tool for identifying and measuring efficacy and effectiveness of rehabilitation services, both through functional profiling and intervention targeting. Existing applications of the ICF in rehabilitation are then surveyed. The ICF, in short, offers an international, scientific tool for understanding human functioning and disability for clinical, research, policy development and a range of other public health uses.

Worldwide Variability in Physical Inactivity : A 51-Country Survey

BACKGROUND Physical inactivity is an important risk factor for chronic diseases, but for many (mainly developing) countries, no prevalence data have ever been published. OBJECTIVE To present data on the prevalence of physical inactivity for 51 countries and for different age groups and settings across these countries. METHODS Data analysis (conducted in 2007) included data from 212,021 adult participants whose questionnaires were culled from 259,526 adult observations from 51 countries participating in the World Health Survey (2002-2003). The validated International Physical Activity Questionnaire (IPAQ) was used to assess days and duration of vigorous, moderate, and walking activities during the last 7 days. RESULTS Country prevalence of physical inactivity ranged from 1.6% (Comoros) to 51.7% (Mauritania) for men and from 3.8% (Comoros) to 71.2% (Mauritania) for women. Physical inactivity was generally high for older age groups and lower in rural as compared to urban areas. CONCLUSIONS Overall, about 15% of men and 20% of women from the 51 countries analyzed here (most of which are developing countries) are at risk for chronic diseases due to physical inactivity. There were substantial variations across countries and settings. The baseline information on the magnitude of the problem of physical inactivity provided by this study can help countries and health policymakers to set up interventions addressing the global chronic disease epidemic.