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Methods to Measure Mortality. SMART Meeting July 14, 2004. Quadrat Sampling. Beldangi Camp, Nepal. Community Map (IDP camp in Gulu, Uganda). Measuring Mortality. What is the context/setting in which we are gathering information? Type of disaster/emergency Phase of emergency
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Methods to Measure Mortality SMART Meeting July 14, 2004
Measuring Mortality • What is the context/setting in which we are gathering information? • Type of disaster/emergency • Phase of emergency • Setting (urban/rural, scattered/concentrated, mixed/unmixed) • Resources: human, financial • Constraints: time, security, geography
Measuring Mortality • What level of precision do we need? • What are the impacts of an imprecise estimate? • We could fail to deliver a life-saving intervention to people who need it • We could waste resources
Measuring Mortality • What methods are most appropriate and in what sequence? • Preparedness planning • Observation • Participatory appraisal • Surveys • Surveillance • In-depth sector assessments • Validation/cross-checking/triangulation
Methods to Assess Mortality Sphere Project’s Minimum Standards in Health Services: Initial Assessment • Total disaster-affected population • Sex and age breakdown (at least <5 and >5) • Average family and household size • Crude mortality ( deaths per 10,000 per day) • Under-5 mortality (deaths per 10,000 per day) • Age and sex-specific incidence rates of major problems and diseases
Methods to Assess Mortality • Observation • Body counts, burial/cremation site activity • Participatory Appraisal • Community/key informant estimates: ask numbers of deaths in last day/week/month, general age groups, pre-arrival/post-arrival, cause of death • Community mapping: locate health clinics, places of worship). Ask about mortality patterns, customs about death (rituals, taboos, disposal of the body, etc.)
Methods to Assess Mortality • Surveillance • Passive: Clinic data • Active: Burial sites, body counts, neighborhood interviews • Surveys • Cross-checking of data sources
Active vs. Passive Surveillance, Bangladesh Camps, 1992 (Diskett, 2003)
Cambodia (Kampuchea), 1962 (Holck and Cates, 1982)
Mortality Rates • Mortality • Crude Death Rate (CDR or CMR) = deaths during interval/mid-interval population • Infant Mortality Rate (IMR) = deaths of infants under 1 year/ 1,000 live births • Under-Five Mortality Rate (U5MR) = deaths of children <5/ 1,000 live births (as used by UNICEF, WHO, etc. expresses the probability of dying by exact age 5 [ 5q0]) • Not to be confused with Age-Specific Death Rate of Children <5 (ASDR-U5 or U5DR)= deaths of children <5/ mid-interval pop. of children <5
Methods to Assess Mortality • Calculating Crude Death Rate CDR=deaths during interval/mid-interval population • Question: A local official tells you of reports of 50 deaths among 10,000 IDPs. What is the CDR, calculated as deaths/10,000/day?
Methods to Assess Mortality • Calculating Crude Death Rate CDR=deaths during interval/mid-interval population • Answer: Trick question. You cannot calculate the Crude Death Rate because you are given no time period within which these deaths reportedly occurred.
Methods to Assess Mortality • Calculating Crude Death Rate CDR=deaths during interval/mid-interval population • Question: You have done a survey of IDPs and found that in a sample of 5,000 people, 15 deaths were reported in the last month. What is the CDR, calculated as deaths/10,000/day?
Methods to Assess Mortality • Answer: 15 deaths/5,000/30 days = 30 deaths/10,000/30 days= 1 death/10,000/day or 15/deaths/5,000/30 days= 0.5/deaths/5,000/day= 1 death/10,000/day
Methods to Assess Mortality • Units of expression are adjustable: For example, 1 death/10,000/day=36.5 deaths/1,000/year = 3.65% of the population died in one year • The Crude Mortality Rate includes all causes of death for all age groups, thus is sensitive to age composition.
Methods to Assess Mortality • Mortality rates should be standardized from camps/settlements/critical areas to national, baseline rates or other comparative data. • Mortality survey instruments should gather data on events that contribute to exposure time: deaths, births, in-migration and out-migration.
Methods to Assess Mortality • Things to think about in designing mortality surveys: • Is this for response or “for the record?” • What level of precision is needed? • What period of reporting or recall is used? • What events contribute to h’hold change, exposure time? • What kinds of death may be more critical to the life of the population? • How to define h’hold, family? • How frequently surveys are conducted?
Methods to Assess Mortality • Reporting/recall periods • periods may be shorter (30 days) or longer (1 year) but must be consistent and stable • shorter periods: • miss earlier mortality trends • highly sensitive to “calendar” error • may capture relatively small number of deaths (1 death/10,000/day = 15 deaths/5,000/month)
Methods to Assess Mortality • Mortality surveys are sensitive to error: • recall error • “calendar” error • age heaping/digit preference (numbers ending in 0 or 5) • age misreporting (children <1 often identified as 1, adults tend to overstate age) • sensitivity/taboos about death
Methods to Assess Mortality • Mortality surveys are sensitive to error: • Mistranslation • Interviewer error • Data-entry error • Analytic error
Methods to Assess Mortality • Mortality surveys • Recommended sample size: 900 households (30 x 30 cluster sample) • Recommended recall period: 6 months - 1 year • Capture key events that contribute to household change, exposure time • Get age, sex, date, cause of death • If using a questionnaire, pre-test, back-translate • Use timeline and/or seasonal calendar to help people recall ages, dates.
Methods to Assess Mortality • Mortality surveys • Participate with decision-makers, stake-holders to define objectives, necessary precision • Establish survey, sampling methodology • Identify and document survey, sampling design (note departures from plan) • Establish and document training curriculum • Establish and document analysis plan • Document and share results promptly