Effect of Climate Factors on the Childhood Pneumonia in Papua New Guinea: A Time-Series Analysis
Abstract
:1. Introduction
2. Materials and Methods
2.1. Study Area
2.2. Data Sources
2.3. Variables in This Study
2.4. Statistical Analysis
2.5. GAM and GLM Analysis
2.6. Meta-Analysis in the Six Areas
3. Results
3.1. General Characteristics of the Study Areas
3.2. Seasonal Variation in Variables and Correlations of Childhood Pneumonia Cases and Climate Variables
Variables | Season | Daru (Western Province) | Port Moresby | Central Province | Eastern Highland Province | East Sepik Province | Madang Province |
---|---|---|---|---|---|---|---|
Population density (person/km2) | 2.4 ± 0.3 | 2468.0 ± 373.0 | 5.7 ± 0.4 | 30.4 ± 1.7 | 6.5 ± 0.4 | 51.3 ± 4.8 | |
Population under five years old† | 20,166 | 90,391 | 27,989 | 49,365 | 51,931 | 59,310 | |
Pneumonia under five years old (/month) | Total | 188.3 ± 67.6 | 1809.9 ± 637.8 | 491.3 ± 119.4 | 1780.3 ± 651.0 | 1434.2 ± 323.8 | 1481.4 ± 287.5 |
Rainy | 181.2 ± 79.4 | 1764.2 ± 655.7 | 487.0 ± 101.6 | 1567.1 ± 570.8 * | 1381.5 ± 300.1 | 1491.3 ± 318.6 | |
Dry | 195.4 ± 52.4 | 1855.6 ± 616.0 | 495.7 ± 134.7 | 1993.6 ± 656.4 * | 1487.0 ± 337.7 | 1471.6 ± 252.2 | |
Incidence (/month, /1000 persons) | Total | 9.4 ± 3.2 | 25.6 ± 10.3 | 19.6 ± 4.6 | 39.1 ± 14.0 | 30.8 ± 6.7 | 28.9 ± 5.7 |
Rainy | 9.0 ± 3.7 | 25.2 ± 11.3 | 19.5 ± 4.2 | 34.4 ± 12.3 * | 29.6 ± 6.2 | 29.2 ± 6.5 | |
Dry | 9.9 ± 2.6 | 26.0 ± 9.1 | 19.7 ± 5.0 | 43.8 ± 14.1 * | 31.9 ± 7.0 | 28.7 ± 4.9 | |
Rainfall (mm/month) | Total | 159.7 ± 161.6 | 100.1 ± 101.6 | 100.1 ± 101.6 | 167.6 ± 106.6 | 193.3 ± 89.1 | 281.6 ± 166.3 |
Rainy | 180.8 ± 132.1 | 135.0 ± 97.0 * | 135.0 ± 97.0 * | 196.2 ± 119.3 * | 171.1 ± 68.3 * | 323.7 ± 138.9 * | |
Dry | 138.6 ± 184.1 | 65.3 ± 93.8 * | 65.3 ± 93.8 * | 139.0 ± 82.7 * | 215.5 ± 101.2 * | 239.6 ± 180.3 * | |
Mean of daily maximum temperature (°C) ‡ | Total | 30.1 ± 1.4 | 31.3 ± 1.1 | 31.3 ± 1.1 | 26.4 ± 0.7 | 30.8 ± 0.4 | 30.9 ± 0.5 |
Rainy | 31.3 ± 0.7 * | 32.1 ± 0.7 * | 32.1 ± 0.7 * | 26.8 ± 0.6 * | 30.9 ± 0.4 * | 31.2 ± 0.4 * | |
Dry | 29.0 ± 0.9 * | 30.6 ± 0.8 * | 30.6 ± 0.8 * | 26.0 ± 0.6 * | 30.7 ± 0.4 * | 30.6 ± 0.5 * | |
SOI | Total | −1.61 ± 10.90 | |||||
Rainy | 0.43 ± 11.32 * | ||||||
Dry | −3.64 ± 10.06 * | ||||||
DMI | Total | 0.06 ± 0.99 | |||||
Rainy | −0.01 ± 1.10 | ||||||
Dry | 0.12 ± 0.86 | ||||||
Malnutrition (persons) | Total | 17.3 ± 56.5 | 44.5 ± 67.3 | 27.4 ± 23.3 | 53.0 ± 37.4 | 54.7 ± 39.5 | 39.1 ± 26.9 |
Rainy | 11.4 ± 12.3 | 39.9 ± 29.6 | 27.8 ± 22.9 | 54.4 ± 43.7 | 45.3 ± 34.3 * | 36.1 ± 23.7 | |
Dry | 23.2 ± 78.5 | 49.1 ± 90.2 | 27.0 ± 23.7 | 51.6 ± 29.6 | 64.2 ± 42.0 * | 42.1 ± 29.4 |
3.3. Fitness of the Statistical Models (Degree of Freedoms, Autocorrelation and Collinearity).
Variables | Season | Daru (Western Province) | Port Moresby | Central Province | Eastern Highland Province | East Sepik Province | Madang Province |
---|---|---|---|---|---|---|---|
Rainfall (mm/month) | Total | −0.001 | 0.107 | 0.107 | −0.028 | 0.126 | 0.188 * |
Rainy | −0.031 | 0.058 | 0.063 | 0.138 | 0.144 | 0.080 | |
Dry | 0.099 | 0.297 * | 0.232 | −0.013 | 0.045 | 0.321 * | |
SOI | Total | −0.164 | −0.048 | −0.130 | −0.116 | −0.060 | −0.077 |
Rainy | −0.216 | −0.045 | −0.047 | −0.032 | 0.055 | −0.080 | |
Dry | −0.085 | −0.042 | −0.215 | −0.009 | −0.095 | −0.056 | |
DMI | Total | 0.051 | 0.133 | −0.184 * | −0.146 | −0.221 * | −0.223 * |
Rainy | 0.148 | 0.215 | −0.144 | −0.110 | −0.173 | −0.139 | |
Dry | −0.026 | 0.065 | −0.246 | −0.379 * | −0.334 * | −0.338 * | |
Dry season | Total | 0.113 | 0.087 | −0.003 | 0.353 * | 0.140 | −0.001 |
Malnutrition (cases) | Total | 0.364 * | 0.306 * | 0.081 | 0.473 * | 0.324 * | 0.205 * |
Rainy | 0.471 * | 0.370 * | −0.100 | 0.571 * | 0.155 | 0.149 | |
Dry | 0.263 * | 0.246 | 0.265 * | 0.398 * | 0.432 * | 0.227 |
3.4. Generalized Additive Model and Generalized Linear Model
Climate Factors | RR (95% CI) | |||||
---|---|---|---|---|---|---|
Daru (Western Province) | Port Moresby | Central Province | Eastern Highland Province | East Sepik Province | Madang Province | |
Rainfall (10 mm/month) | 0.999 | 1.009 * | 1.004 * | 1.002 | 1.001 | 1.001 |
(0.994–1.003) | (1.003–1.015) | (1.000–1.009) | (0.996–1.008) | (0.996–1.005) | (0.999–1.003) | |
Mean of daily maximum temperature (°C) ‡ | 1.090 | 1.079 | 1.061 * | 0.970 | 1.025 | 1.035 |
(0.998–1.189) | (0.999–1.165) | (1.003–1.122) | (0.886–1.062) | (0.918–1.145) | (0.953–1.122) | |
SOI | 0.996 | 0.994 | 0.993 * | 0.990 | 0.995 | 0.995 * |
(0.988–1.004) | (0.987–1.001) | (0.988-0.997) | (0.987–1.001) | (0.990–1.000) | (0.991-.999) | |
DMI | 1.029 | 0.989 | 0.952 | 0.925 | 0.946 | 0.949* |
(0.933–1.134) | (0.914–1.070) | (0.898–1.008) | (0.846–1.010) | (0.891–1.003) | (0.903-.997) | |
Season† | 1.276 * | 1.220 * | 1.117 | 1.240 * | 1.064 | 1.002 |
(1.018–1.599) | (1.041–1.428) | (0.995–1.253) | (1.083–1.420) | (0.982–1.153) | (0.928–1.082) |
4. Discussion
5. Conclusions
Supplementary Materials
Acknowledgments
Author Contributions
Conflicts of Interest
Abbreviations
CI | confidence interval |
DMI | dipole mode index |
ENSO | El Niño southern oscillation |
GAM | generalized additive model |
GLM | generalized linear model |
IOD | Indian Ocean dipole |
NDOH | National Department of Health, Papua New Guinea |
NHIS | National Health Information System (Papua New Guinea) |
PNG | Papua New Guinea |
RR | relative risk |
SOI | southern oscillation index |
ACF | autocorrelation function |
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Share and Cite
Kim, J.; Kim, J.-H.; Cheong, H.-K.; Kim, H.; Honda, Y.; Ha, M.; Hashizume, M.; Kolam, J.; Inape, K. Effect of Climate Factors on the Childhood Pneumonia in Papua New Guinea: A Time-Series Analysis. Int. J. Environ. Res. Public Health 2016, 13, 213. https://doi.org/10.3390/ijerph13020213
Kim J, Kim J-H, Cheong H-K, Kim H, Honda Y, Ha M, Hashizume M, Kolam J, Inape K. Effect of Climate Factors on the Childhood Pneumonia in Papua New Guinea: A Time-Series Analysis. International Journal of Environmental Research and Public Health. 2016; 13(2):213. https://doi.org/10.3390/ijerph13020213
Chicago/Turabian StyleKim, Jinseob, Jong-Hun Kim, Hae-Kwan Cheong, Ho Kim, Yasushi Honda, Mina Ha, Masahiro Hashizume, Joel Kolam, and Kasis Inape. 2016. "Effect of Climate Factors on the Childhood Pneumonia in Papua New Guinea: A Time-Series Analysis" International Journal of Environmental Research and Public Health 13, no. 2: 213. https://doi.org/10.3390/ijerph13020213