Table 1.
Summary of studies included in the systematic review and meta-analysis of effect of climatic factors and altitude on tuberculosis
Study | Country, Population | Study period | Outcome type |
---|---|---|---|
24 | Japan, all registered TB cases of the Fukuoka Institute of Health | 2008-2012 | All forms of TB incidence (5904 TB cases) |
21 | China, all annual reported TB patients in 32 Mainland provinces | 2009-2013 | TB prevalence |
25 | Japan, TB patients registered in 46 prefectures Japanese TB registry | 1961-1978 | TB prevalence determined by clinicians by clinical factors |
29 | China, all TB patients in randomly selected medical institutions | 2009-2013 | TB incidence (n=27, 655 cases) |
27 | Turkey, all patients receive treatment in state TB dispensaries from randomly selected 56 cities | 1999-2005 | All forms of TB (378 TB cases; the mean incidence of TB per 100 k=23.8±9.1 [12.07-47.39]) |
28 | Mexico, all annual PTB notification cases registered obtained from Mexican Health Ministry database | 1998, 2002 | TB incidence |
23 | Kenya, all annual TB patient reports in 41 districts of National TB Program | 1988-1990 | TB prevalence |
26 | China, all registered TB cases from Chinese center of disease control and prevention management information system | 2007 | TB prevalence |
22 | China, all TB patients registered (in 31 provinces) China Health Statistics Yearbook | 2001-2010 | TB prevalence |
Study | Exposure | Adjusted variable | Findings |
24 | Temperature (29.2°C) | Age, sex | Exposure to extreme heat temperature (RR=1.2, 95% CI: 1.01-1.43) |
21 | Monthly average temperature | NA | Average annual temperature (RR=1.00324, 95% CI: 1.00150-1.00550) |
25 | Annual average temperature (°C) | Sunshine hour | The monthly average temperature increase in 10°C TB incidence decrease by 9% (β=−0.0060, P<0.001) |
27 | Monthly average temperature (°C) | Latent variable; TB control programs, population density, income, public assist, past TB control, past epidemic | 29.9°C-39.8°C and 18.0°C-46.1°C temperature is associated with TB prevalence and incidence rate, respectively |
28 | Altitude defined as>750 m and 1-750 m | Green card, annual income, population density, household size, urbanization rate, number of doctors | There is inverse correlation between altitude and mean TB incidence (r=−0.58, 95% CI: −0.73-−0.38, P=0.000) The incidence higher in cities at an altitude <750 m versus >750 m (OR=3.28, 95% CI [1.83-5.88], P<0.0001) |
23 | Altitude above sea level (0-2500) | NA | Altitude above sea level correlated with TB incidence (r=−0.74, 95% CI: −0.87-−0.53, P<0.0001) |
26 | Altitude | Nomads, population density, literacy rate, household size, life expectancy rate, nutritional status | The log notification rates negatively associated with altitude (r=−0.71, 95% CI: −0.51-0.83, P<0.001) |
22 | Altitude | Air quality, education, health service, population density, economic level, unemployment | Altitude factor (−0.595) had a significant effect on TB prevalence |
NA: No information about variable adjustment, TB: Tuberculosis, CI: Confidence interval, RR: Relative risk, OR: Odds ratio