GH at Universität Göttingen

Number of years a newborn infant would live if prevailing patterns of mortality at the time of its birth would prevail

• Mortality converges to 1
• Calculated conditionally (e.g. life expectancy of an 87 year old is 90)
• High child mortality generally affects life expectancy (negatively)
• Potential to improve the life expectancy is very large in countries with high child mortality

• Gives the probability of a child dying before reaching 5 years of age
• Probability of accidental and non-accidental death included

• Generally, dependant on the technological frontier, better access to care and modern equipment leads to lower death-probabilities
• U5-mortatlity was greatly decreased in the last 100 years due to improved sanitation and water, also due to reduction of unnecessary infections

• Number of infants dying before reaching one year of age, per given year
• Many infants die within the first month after birth

• Number of neonatals dying before reaching 28 days of age, in a given year
• Worldwide on average over half of under 5 deaths occur in the first 28 days after birth
• Improvements of neonatal mortality are small, as it is much harder to prevent complications with child birth

• Number of women who die from pregnancy related causes while pregnant or within 42 days of pregnancy termination
• Very stark contrast between Europe and Sub-Saharan Africa

• Summary metric of population health
• One DALY = one year of healthy life lost
• The sum of DALYs of the total population is a measurement of the gap between the current health status and the ideal health situation

• DALY = Years of life lived with disability (YLD) + Years of life lost (YLL)
• YLD = Number of prevalent cases (P) * disability weight (DW)
• DW is between 0 and 1 e.g. severe depression = 0,658 ; infertility = 0,008

• Early studies to measure disability weight relied on the opinions of medical staff (this was later discarded as it was seen as too elitist)
• Newer studies use the consensus of the general population (via face-to-face interviews, telephone interviews or web surveys)
• Age weighting is no longer taken into account

The burden of mental illness is often underrepresented, for 5 reasons:

•  Overlap between psychiatric and neurological disorders (e.g. schizophrenia)
• Suicide and self-harm are grouped into separate categories outside the boundary of measurement
• Chronic pain syndromes are conflated with muscosekletal disorders
• The contribution of severe mental illness is inadequate for mortality
• Personality disorders are excluded in mental illness disease burden calculations 

• Risk factor: An aspect of personal behaviour or lifestyle, an environmental exposure, an inborn or inherited characteristic, that on the basis of epidemiological evidence is known to be associated with health-related conditions considered important to prevent (e.g. smoking)