South African Psychiatry - February 2019

FEATURE
FOR 2016, STATISTICS SOUTH AFRICA
FOUND MENTAL ILLNESS TO ACCOUNT
FOR 0.5% OF DEATHS, 8 USING THE ICD-10
DEFINITION OF UNDERLYING CAUSE OF
DEATH AS ‘THE DISEASE OR INJURY THAT
INITIATED THE SEQUENCE OF EVENTS
LEADING DIRECTLY TO DEATH’ OR ‘THE
CIRCUMSTANCES OF THE ACCIDENT OR
VIOLENCE THAT PRODUCED THE FATAL
INJURY’.
However, in their meta-analysis on mortality among
people with mental illness, Walker et al, 9 calculated
a pooled relative risk of 2.22 (95% CI, 2.12–2.33)
compared to the general population, with a median
of 10 years of potential life lost. Two-thirds of deaths
were due to natural causes, mainly cardiopulmonary
disease; 17.5% were of unnatural cause and the
remainder were unknown. They estimated that
mental illness could account for 14.3% of the global
burden of disease through higher rates of premature
mortality.
MORTALITY STATISTICS
IT WAS THE DEATH OF 36 PEOPLE WHICH
CAUSED THE INVESTIGATION INTO LIFE
ESIDIMENI. WHEN THE OMBUD RELEASED
HIS REPORT, 94 PEOPLE HAD DIED. A FEW
MONTHS LATER, THE MEDIA REPORTED
OVER 140 DEATHS. ALL THESE FIGURES
ARE MEANINGLESS WITHOUT CONTEXT
(THE HUMAN RIGHT TO DIGNITY) AND
WITHOUT COMPARISON TO THE NUMBER
OF DEATHS EXPECTED (THE HUMAN
RIGHT TO LIFE).
Most mortality analyses among people with mental
illness are cohort studies where a group of people
are followed over at least one year, with comparison
of the cohort death rate to that of the general
population.
CRUDE DEATH RATE
The crude death rate is calculated as the number of
deaths for a given year per 1000 people. 10
IN 2016, THE CRUDE DEATH RATE FOR
SOUTH AFRICA WAS 10/ 1000 PEOPLE, 11
TWO POINTS HIGHER THAN THE WORLD
CRUDE DEATH RATE OF 8/ 1000 PEOPLE.
Other countries with a crude death rate of 10/ 1000 in
2016 include Belgium, Finland, Italy, Poland, Slovenia,
the Democratic Republic of the Congo, Cameroon
and Mozambique. At 9/ 1000 people, the crude
death rate of high-income countries was greater
than that of LMICs, which stood at 7/ 1000 people
for 2016. Context is necessary to give meaning to the
crude death rate. For example, a country with a low
birth rate and aging population may have a higher
crude death rate than a low-income country with a
high infant and child mortality rate but a growing,
predominantly young population.
AGE-ADJUSTED DEATH RATE AND
STANDARDISED MORTALITY RATIO
A life-table provides the death rate of the general
population in age categories for a period of time
(usually a calendar year). The age-adjusted death
rate reflects the number of deaths that would have
occurred if the general population had of died at the
same rate as the study population within the same
age categories and over the same time period. The
Standardised Mortality Ratio (SMR) is the ratio of the
observed deaths in the study population in each
age group to the deaths (the expected deaths) in
the general population in the same age group and
over the same time period. Thus, in Life Esidimeni, the
overall SMR was found to be highly significant at 4.9
(95% confidence interval 3.92 - 5.80). 12
THIS MEANS THAT, OVERALL THERE WERE
ALMOST 5 MORE OBSERVED DEATHS
THAN WHAT WAS EXPECTED FOR EACH
AGE GROUP.
However, for those over the age of 80 years, although
observed deaths were more than double the
expected deaths, this was not significant (SMR 2.3:
95% confidence interval 0.32 - 4.28).
In essence, the emergence of measures to more
accurately quantify the impact of illness on affected
individuals has led to a more comprehensive
understanding of burden of disease.
REFERENCES
1. World Health Organisation. WHO methods and
data sources for global burden of disease
estimates 2000-2015 Geneva: WHO; 2017 [cited
2018 20 September]. Available from: http://www.
who.int/healthinfo/global_burden_disease/
GlobalDALYmethods_2000_2015.pdf.
2. Whiteford HA, Degenhardt L, Rehm J, Baxter AJ,
Ferrari AJ, Erskine HE, et al. Global burden of
disease attributable to mental and substance
use disorders: findings from the Global Burden of
Disease Study 2010. Lancet. 2013;382(9904):1575-
86.10.1016/S0140-6736(13)61611-6
3. GBD 2015 DALYs and Hale Collaborators. Global,
regional, and national disability-adjusted life-years
(DALYs) for 315 diseases and injuries and healthy
life expectancy (HALE), 1990-2015: a systematic
analysis for the Global Burden of Disease Study
2015. Lancet. 2016;388(10053):1603-58.10.1016/
S0140-6736(16)31460-X
4. Robertson LJ, Szabo CP. Implementing
Community Care in Large Cities and Informal
Settlements: An African Perspective. In: Okkels N,
12 * SOUTH AFRICAN PSYCHIATRY ISSUE 18 2019