health statistics and informatics who's activities on measuring health status

Health Statistics and Informatics


WHO's Activities on Measuring Health Status


Areas of work

• Surveys

• Development of standardised health survey

modules

• Burden of disease


WHO - World Health SurveysWHO - World Health SurveysWHS 2002/03WHS 2002/03

70 SURVEYS in 70 countries 70 SURVEYS in 70 countries

Household - long : 53Household - long : 53

Household - short: 13Household - short: 13

CATI :CATI : 4 4

The boundaries and names shown and the designations used on this map do not imply the expression of any opinion whatsoever on the part of the World Health Organization concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. Dotted lines on maps represent approximate border lines for which there may not yet be full agreement.

© WHO 2002. All rights reserved


SAGE - INDEPTH

The boundaries and names shown and the designations used on this map do not imply the expression of any opinion whatsoever on the part of the World Health Organization concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. Dotted lines on maps represent approximate border lines for which there may not yet be full agreement. © WHO 2005. All rights reserved

•Mexico•South Africa•Ghana

•China•India•Russia

•Kenya•Tanzania•Bangladesh

•Viet Nam•Indonesia


Current Status

• Data collection expected to be completed

at all sites by March 2009

• Data collection completed at all eight

INDEPTH sites

• Data sets in public domain by mid 2010


Future directions

• Longitudinal follow up

• Improve understanding of non-fatal health outcomes /

disability - determinants

• Continue to develop methods to improve measurement, e.g.,

health states, risk factors, effect of interventions

• Develop standard survey modules for health

• Link survey to demographic surveillance data – INDEPTH

• Promote use of methods in other international studies

• Create a data collection platform to monitor health trends

and determinants over time


Standardised Health Modules - objectives• To provide easy access to standardized and validated survey

questions and modules, including those for the collection of biomarkers, with systematic documentation

• To enhance harmonization of survey modules between international and national surveys by developing common standards for health survey modules and joint standards for health expenditure modules in surveys

• To make survey modules core indicator driven, and define minimum contents

• To facilitate the establishment of a survey module driven approach to country (health) surveys, in line with national plans and data needs


Standardised Health Modules - rationale

• Generate comparable data over time and between populations

• Limit the application of poorly tested survey modules and questions, often driven by the flavour of the day

• Promote a more flexible system of survey implementation

• More critical and systematic assessment of the utility, reliability and validity of survey questions


Standardised Health Modules - topicsSubject areas• Mortality

• Child mortality: birth history, recall births and deaths• Maternal & Adult mortality: sibling history, recent

deaths• Causes of death: verbal autopsy, death certificates

• Morbidity & health states

• Health states: self reported health in specific domains• Chronic conditions (diabetes, heart disease, asthma,

COLD, arthritis, cancers, depression/mental conditions): recall diagnosis, symptoms with algorithms, biological and clinical testing

• HIV/AIDS• Acute diseases: recall last 2 weeks (diarrhoea,

respiratory illness -mostly children); malaria• Intervention coverage

• MCH preventive interventions: immunization coverage, maternal and neonatal care, PMTCT, FP etc.

• MCH treatment interventions: recall treatment practices

• Chronic conditions: recall treatment practices• Risk factors and determinants

• Risk factors children: water and sanitation, nutritional status/feeding practices, indoor air pollution etc.

• Risk factors adults: smoking, overweight, dietary recall, sexual behaviour, alcohol use, physical exercise

• Socioeconomic and cultural determinants: wealth, income, education, ethnicity, religion

• Violence• Health systems

• Health expenditure: income, detailed expenses on health in last year

• Responsiveness: self reported perception and satisfaction

• Biomarkers

Existing modules

• Birth history• Antenatal and delivery care / maternal and neonatal

care• Birth history• Verbal autopsy• Family planning; fertility preferences• Immunization• Child morbidity and treatment• Child nutrition and feeding patterns• Maternal nutrition• Adult Chronic conditions and treatment• Health service utilization• HIV/AIDS; Malaria• Violence against women• Maternal mortality – sibilinghood• Etc.

Indicators• Specific set of questions required for each indicator


Standardised Health Modules - process

1. Define the purpose, indicators and analytical dimensions of the module

2. Review the literature with regard to measurement strategies for the outcome of interest with specific regard to strengths and weaknesses of different approaches, their reliability and validity

3. Build a repository of items from existing questionnaires including item wording, response options, accompanying interviewer instructions and training guidelines, and other technical documentation as appropriate

4. Do a systematic comparison of items across different instruments to produce cross-walks across different surveys and other modes of data collection

5. Document the similarities and differences in the method used for data collection – including mode of administration, sampling design, level of data collection, target population and respondent characteristics

6. Develop a standard and consistent set of minimum questions for a given topic module and if appropriate a second more detailed set of questions

7. Produce modules with a set of questions which embody best practice in the area accompanied by information on routing, mode of interview, editing instructions and a basic tabulation plan

8. Develop a testing protocol to demonstrate the utility, feasibility, reliability and validity of items for each module.


Global burden of Disease (GBD)

A standardized framework for integrating all available information on mortality, causes of death, individual health status, and condition-specific epidemiology to provide an overview of the levels of population health and the causes of loss of health

• Consistent, comprehensive descriptive epidemiology

• Common metric or summary measure


DALY = YLL + YLD

Disability Adjusted Life Years

Time is used as the common metric for mortality and health states

YLL Years of life lost due to mortality

YLD Equivalent years (of healthy life) lost due to

disability


Years Lived With disability YLD = I x L x DW

YLD = Years of life lived with disabilityI = Number of incident cases in the populationDW = Average disability weightL = Average duration of disability [years]

4 cases of mild mental retardation (DW=0.36) due to lead exposure in early childhood :

4 x 0.36 x 77.8 years = 112 YLD


The DALY quantifies "health"

• The DALY is now conceptualized as quantifying "health" not the goodness of health (the original conceptualization) or wellbeing/QoL

• Health conceptualized in terms of human functioning capacities in a set of domains/dimensions of health

• Disability is seen as synonymous with loss of health • Decrements in health are decrements in functioning

capacity in one or more health domains• Above a certain threshold in a domain, improvements

may be seen as "talent" rather than increasing "health"• Does health end at the skin? What about aids?• GBD considers some aids close to the skin as

improvements in health (contacts, glasses, hearing aids, basic mobility aids)


GBD Goals

• Measure loss of health due to comprehensive set of disease, injury, and risk factor causes in a comparable way

• Measure population health for the world, and for a set of regions

• Decouple epidemiological assessment and advocacy

• Inject non-fatal health outcomes into health policy debate

• Use a common metric for BOD assessment and intervention analysis that combines mortality and non-fatal outcomes


Ten leading causes of burden of disease, world, 2004 and 2030

health statistics and informatics who's activities on measuring health status

Documents