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Association between temperature change and outpatient visits for respiratory tract infections among children in Guangzhou, China.

Liu Y, Guo Y, Wang C, Li W, Lu J, Shen S, Xia H, He J, Qiu X - Int J Environ Res Public Health (2015)

Bottom Line: A large temperature decrease was associated with a significant risk for an RTI, with the effect lasting for ~10 days.The maximum effect of a temperature drop (-8.8 °C) was reached at lag 2~3 days.Children aged 0-2 years, and especially those aged <1 year, were particularly vulnerable to the effects of temperature drop.

View Article: PubMed Central - PubMed

Affiliation: Division of Birth Cohort Study, Guangzhou Women and Children's Medical Center, Sun Yat-sen University, 9 Jinsui Road, Guangzhou 510623, China. PH04LY@163.com.

ABSTRACT
The current study examined the association between temperature change and clinical visits for childhood respiratory tract infections (RTIs) in Guangzhou, China. Outpatient records of clinical visits for pediatric RTIs, which occurred from 1 January 2012 to 31 December 2013, were collected from Guangzhou Women and Children's Hospital. Records for meteorological variables during the same period were obtained from the Guangzhou Meteorological Bureau. Temperature change was defined as the difference between the mean temperatures on two consecutive days. A distributed lag non-linear model (DLNM) was used to examine the impact of temperature change on pediatric outpatient visits for RTIs. A large temperature decrease was associated with a significant risk for an RTI, with the effect lasting for ~10 days. The maximum effect of a temperature drop (-8.8 °C) was reached at lag 2~3 days. Children aged 0-2 years, and especially those aged <1 year, were particularly vulnerable to the effects of temperature drop. An extreme temperature decrease affected the number of patient visits for both upper respiratory tract infections (URTIs) and lower respiratory tract infections (LRTIs). A temperature change between consecutive days, and particularly an extreme temperature decrease, was significantly associated with increased pediatric outpatient visits for RTIs in Guangzhou.

No MeSH data available.


Related in: MedlinePlus

Relative risk of an outpatient visit for a respiratory tract infection (RTI) by temperature change (°C), days of lag, and RTI classification (upper RTIs (URTIs) and lower RTIs (LRTIs)). The reference value was 0 °C temperature change.
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ijerph-12-00439-f005: Relative risk of an outpatient visit for a respiratory tract infection (RTI) by temperature change (°C), days of lag, and RTI classification (upper RTIs (URTIs) and lower RTIs (LRTIs)). The reference value was 0 °C temperature change.

Mentions: The overall effects of temperature change on daily outpatient visits for RTIs are depicted in Figure 2. The plot shows a nonlinear relationship between temperature and patient visits for RTIs. Inspection of the 3-D graph suggests that a large temperature decrease coincided with an immediate increase in the number patient visits for RTIs, while an increase coincided with a decreased number of visits. The maximum effect of a temperature drop (−8.8 °C) was reached at lag days 2~3 after its occurrence (RR: 1.16; 95% CI: 1.11, 1.22). As illustrated in Figure 3, the RR of RTIs by temperature change at specific lag periods (0, 5, 10, and 20 days) and by the lag at specific temperature changes (−6.2, −3.5, 2.9, and 3.8 °C), corresponded to approximately the 1st, 5th, 95th, and 99th percentiles, respectively, of the temperature change distribution in Guangzhou. The effects of temperature change on daily outpatient visits for RTIs changed with different lags periods, and the effect seemed to disappear at lag 20 (Figure 3, left). These results confirmed both the delayed effect of an extreme temperature decrease (−6.2 °C), and the significant resultant risk which lasted up to ~10 days (Figure 3, right). The association between temperature change and outpatient visits for RTIs by age group is presented in Figure 4. In Guangzhou, children aged ≤2 years, and especially those <1-year-old, were vulnerable to a sharp drop in temperature, while they were protected by a temperature increase. Children aged ≤2 years were most affected by a temperature change at lag days 10~15. The greatest effects of an extreme temperature decrease (−6.2 °C) on children aged <1-year and 1–2 years occurred on lag day five (RR: 1.08; 95% CI: 1.05, 1.11) and on the current day (lag day 0) (RR: 1.04, 95% CI: 1.01, 1.07), respectively (Table 2). A temperature change did not significantly affect the number of patient visits for RTIs by individuals aged >6 years. The relationship between temperature change and outpatient visits for URTIs and LRTIs at different lag periods is shown in Figure 5. While an extreme temperature decrease affected visits for both URTIs and LRTIs, the effects were more significant on outpatient visits for LRTIs.


Association between temperature change and outpatient visits for respiratory tract infections among children in Guangzhou, China.

Liu Y, Guo Y, Wang C, Li W, Lu J, Shen S, Xia H, He J, Qiu X - Int J Environ Res Public Health (2015)

Relative risk of an outpatient visit for a respiratory tract infection (RTI) by temperature change (°C), days of lag, and RTI classification (upper RTIs (URTIs) and lower RTIs (LRTIs)). The reference value was 0 °C temperature change.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4306872&req=5

ijerph-12-00439-f005: Relative risk of an outpatient visit for a respiratory tract infection (RTI) by temperature change (°C), days of lag, and RTI classification (upper RTIs (URTIs) and lower RTIs (LRTIs)). The reference value was 0 °C temperature change.
Mentions: The overall effects of temperature change on daily outpatient visits for RTIs are depicted in Figure 2. The plot shows a nonlinear relationship between temperature and patient visits for RTIs. Inspection of the 3-D graph suggests that a large temperature decrease coincided with an immediate increase in the number patient visits for RTIs, while an increase coincided with a decreased number of visits. The maximum effect of a temperature drop (−8.8 °C) was reached at lag days 2~3 after its occurrence (RR: 1.16; 95% CI: 1.11, 1.22). As illustrated in Figure 3, the RR of RTIs by temperature change at specific lag periods (0, 5, 10, and 20 days) and by the lag at specific temperature changes (−6.2, −3.5, 2.9, and 3.8 °C), corresponded to approximately the 1st, 5th, 95th, and 99th percentiles, respectively, of the temperature change distribution in Guangzhou. The effects of temperature change on daily outpatient visits for RTIs changed with different lags periods, and the effect seemed to disappear at lag 20 (Figure 3, left). These results confirmed both the delayed effect of an extreme temperature decrease (−6.2 °C), and the significant resultant risk which lasted up to ~10 days (Figure 3, right). The association between temperature change and outpatient visits for RTIs by age group is presented in Figure 4. In Guangzhou, children aged ≤2 years, and especially those <1-year-old, were vulnerable to a sharp drop in temperature, while they were protected by a temperature increase. Children aged ≤2 years were most affected by a temperature change at lag days 10~15. The greatest effects of an extreme temperature decrease (−6.2 °C) on children aged <1-year and 1–2 years occurred on lag day five (RR: 1.08; 95% CI: 1.05, 1.11) and on the current day (lag day 0) (RR: 1.04, 95% CI: 1.01, 1.07), respectively (Table 2). A temperature change did not significantly affect the number of patient visits for RTIs by individuals aged >6 years. The relationship between temperature change and outpatient visits for URTIs and LRTIs at different lag periods is shown in Figure 5. While an extreme temperature decrease affected visits for both URTIs and LRTIs, the effects were more significant on outpatient visits for LRTIs.

Bottom Line: A large temperature decrease was associated with a significant risk for an RTI, with the effect lasting for ~10 days.The maximum effect of a temperature drop (-8.8 °C) was reached at lag 2~3 days.Children aged 0-2 years, and especially those aged <1 year, were particularly vulnerable to the effects of temperature drop.

View Article: PubMed Central - PubMed

Affiliation: Division of Birth Cohort Study, Guangzhou Women and Children's Medical Center, Sun Yat-sen University, 9 Jinsui Road, Guangzhou 510623, China. PH04LY@163.com.

ABSTRACT
The current study examined the association between temperature change and clinical visits for childhood respiratory tract infections (RTIs) in Guangzhou, China. Outpatient records of clinical visits for pediatric RTIs, which occurred from 1 January 2012 to 31 December 2013, were collected from Guangzhou Women and Children's Hospital. Records for meteorological variables during the same period were obtained from the Guangzhou Meteorological Bureau. Temperature change was defined as the difference between the mean temperatures on two consecutive days. A distributed lag non-linear model (DLNM) was used to examine the impact of temperature change on pediatric outpatient visits for RTIs. A large temperature decrease was associated with a significant risk for an RTI, with the effect lasting for ~10 days. The maximum effect of a temperature drop (-8.8 °C) was reached at lag 2~3 days. Children aged 0-2 years, and especially those aged <1 year, were particularly vulnerable to the effects of temperature drop. An extreme temperature decrease affected the number of patient visits for both upper respiratory tract infections (URTIs) and lower respiratory tract infections (LRTIs). A temperature change between consecutive days, and particularly an extreme temperature decrease, was significantly associated with increased pediatric outpatient visits for RTIs in Guangzhou.

No MeSH data available.


Related in: MedlinePlus