HDSS Mortality Data

Mortality indicators available are Crude death rate (CDR), Age-standardised crude death rate (ASCDR), Age-specific mortality rates (ASMR), Neonatal mortality rate per 1000 person-years, Neonatal mortality rate per 1000 live births, Infant mortality rate 1q0, Child mortality rate 4q1, Under-five mortality rate 5q0, Adult mortality rate 45q15 and Life expectancy at birth e0.

Mortality
Mortality is measured using the number of deaths of HDSS residents.

Crude death rate (CDR)
CDR is the number of deaths divided by the person-years of all ages, expressed in deaths per 1000 person-years. 
NB: CDR depends on age-structure, which evolves from one calendar year to the next and from one HDSS to the other. Therefore CDRs are not strictly comparable over the period and across HDSS.

Age-standardised crude death rate (ASCDR)
ASCDR is a weighted average of the age-specific mortality rates, expressed in deaths per 1000 person-years. The weights are the proportions of person-years in the corresponding age over the entire period of HDSS observation. 
NB: ASCDR depends on the chosen age-structure, which is different from one HDSS to the other. However ASCDRs are comparable over the calendar years of observation for the same HDSS.

Age-specific mortality rates (ASMR)
ASMR is the number of deaths in a specific age-group divided by the person-years lived in that age-group, expressed in deaths per 1000 person years.

Neonatal mortality rate per 1000 person-years
Neonatal mortality rate is the number of deaths in the first 28 completed days of life divided by the number of person-years lived in the HDSS within the first 28 days, expressed in deaths per 1000 person-years.

Neonatal mortality rate per 1000 live births
Neonatal mortality rate is the standard rate obtained by dividing the number of deaths in the first 28 completed days of life by the number of live births in the HDSS, expressed in deaths per 1000 live births. 
NB: This indicator is slightly biased depending on migrations in and out of the HDSS between birth and 29th day. This is because infants migrating in the HDSS (becoming new residents) after their birth and before their 29th day are counted in the number of deaths if they die, but are not counted as births. Also, infant migrating out of the HDSS before their 29th day are counted among living births, but are not counted as deaths if they die after out-migrating and before their 29th day.
 
Infant mortality rate 1q0
Infant mortality rate is the life-table (Kaplan-Meier) estimate using exact dates of death and of censoring. It is expressed in deaths per 1000 live births and interpreted as the probability to die before 1st birthday.
NB: This indicator is slightly biased depending on migrations in and out of the HDSS between birth and 1st birthday. This is because infants who in-migrated are accounted for if these infants (or their mothers, depending on the HDSS) spent at least the minimum time required to be a resident in the HDSS (if they die during this time span, their death will not be accounted since they are not considered residents), whereas infants who out-migrated are accounted for the total time spent in the HDSS from birth (or age at in-migration) to age at out-migration.

Child mortality rate 4q1
Child mortality rate is the life-table (Kaplan-Meier) estimate using exact dates of death and of censoring. It is expressed in deaths per 1000 person-years surviving their 1st birthday and interpreted as the probability to die between 1st birthday and 5th birthday.
NB: This indicator is slightly biased depending on migrations in and out of the HDSA between 1st birthday and 5th birthday. This is because children who in-migrated are accounted for if these infants (or their mothers, depending on the HDSS) spent at least the minimum time required to be a resident in the HDSA (if they die during this time span, their death will not be accounted since they are not considered residents), whereas children who out-migrated are accounted for the total time spent in the HDSA from 1st birthday (or age at in-migration) to age at out-migration.

Under-five mortality rate 5q0
Under-five mortality rate is the life-table (Kaplan-Meier) estimate using exact dates of death and of censoring. It is expressed in deaths per 1000 live births and interpreted as the probability to die before 5th birthday.
NB: This indicator is slightly biased depending on migrations in and out of the HDSA between birth and 5th birthday. This is because children who in-migrated are accounted for if these children (or their mothers, depending on the HDSS) spent at least the minimum time required to be a resident in the HDSA (if they die during this time span, their death will not be accounted since they are not considered residents), whereas children who out-migrated are accounted for the total time spent in the HDSA from birth (or age at in-migration) to age at out-migration.

Adult mortality rate 45q15
Adult mortality rate is the life-table (Kaplan-Meier) estimate using exact dates of death and of censoring. It is expressed in deaths per 1000 people surviving their 15th birthday and interpreted as the probability to die between 15th birthday and 60th birthday.
NB: This indicator is slightly biased depending on migrations in and out of the HDSA between 15th birthday and 60th birthday. This is because adults who in-migrated are accounted for if they spent at least the minimum time required to be a resident in the HDSA (if they die during this time span, their death will not be accounted since they are not considered residents), whereas adults who out-migrated are accounted for the total time spent in the HDSA from 15th birthday (or age at in-migration) to age at out-migration.

Life expectancy at birth e0
Life expectancy is the life-table (Kaplan-Meier) estimate using exact dates of death and of censoring. It is expressed as an average number of years that a hypothetical cohort would have lived by experiencing the health conditions of a particular calendar year over its lifetime.
NB: This indicator is slightly biased depending on migrations in and out of the HDSA. This is because people who in-migrated are accounted for if they spent at least the minimum time required to be a resident in the HDSA (if they die during this time span, their death will not be accounted since they are not considered residents), whereas people who out-migrated are accounted for the total time spent in the HDSA from 1st birthday (or age at in-migration) to age at out-migration.