Page 61 - Contributed Paper Session (CPS) - Volume 3

CPS1944 Oyelola A.
function for long term temporal trend and seasonality with 8 dfs generated
per year of study. The pneumonia-lag and weather-pneumonia associations
were presented in Figures 2 & 3, respectively with reference at optimum
o
temperature value of 28.8 C (95% empirical confidence interval, eCI: 16.0 -
31.4) and optimum total weekly rainfall value of 332.2 mm (95% eCI: 0 - 516).
Higher pneumonia risk and immediate effect (lag 0) was observed at lower
temperatures while the effect of rainfall is delayed (up to lag 15) at low total
weekly rainfall. The risk associated with rainfall (of 30 mm) appeared significant
after lag of 5 weeks and progressively increases for longer exposure. However,
o
significant risk associated with temperature exposure of 20 C was immediate
and lasted for 1-12 weeks.
Table 1: Summary characteristics of pneumonia cases, weekly
temperature and rainfall.
Variables Mean SD Min Percentile Max Cor. (p-
25 50 75 value)*
Pneumonia cases 15.3 7.94 2.0 10.0 14.0 19.0 62.0
Mean 24.8 3.26 15.98 22.43 25.53 27.51 31.43 -0.224
temperature ( C) (<0.001)
o
Minimum 20.32 4.21 8.78 17.48 21.14 24.07 27.26 -0.217
temperature ( C) (<0.001)
o
Maximum 29.27 2.52 20.27 27.26 29.67 31.27 35.60 -0.218
temperature ( C) (<0.001)
o
Rainfall (mm)
Total weekly 23.5 60.32 0 0 1.4 13.5 516.0 -0.099
(0.017)
Weekly average 3.55 9.29 0 0 0.2 2.0 78.1 -0.118
(0.005)
*Correlation between pneumonia cases and climate variables
Decomposition of additive time series
60
50
observed 40 30
10 20
0
25
20
trend 15
10
4
seasonal 2 0 -2
-4
20
15 10
random 5 0
-10
2006 2008 2010 2012 2014 2016

Time
Fig. 1: Decomposition of weekly cases of pneumonia additive time series
during the study period, 2006-2016.

50 | I S I W S C 2 0 1 9