Relationship of meteorological factors and air pollutants with medical care utilization for gastroesophageal reflux disease in urban area

Abstract

Background: Gastroesophageal reflux disease (GERD) is a highly prevalent disease of the upper gastrointestinal tract, and it is associated with environmental and lifestyle habits. Due to an increasing interest in the environment, several groups are studying the effects of meteorological factors and air pollutants (MFAPs) on disease development.

Aim: To identify MFAPs effect on GERD-related medical utilization.

Methods: Data on GERD-related medical utilization from 2002 to 2017 were obtained from the National Health Insurance Service of Korea, while those on MFAPs were obtained from eight metropolitan areas and merged. In total, 20071900 instances of GERD-related medical utilizations were identified, and 200000 MFAPs were randomly selected from the eight metropolitan areas. Data were analyzed using a multivariable generalized additive Poisson regression model to control for time trends, seasonality, and day of the week.

Results: Five MFAPs were selected for the prediction model. GERD-related medical utilization increased with the levels of particulate matter with a diameter ≤ 2.5 μm (PM_2.5) and carbon monoxide (CO). S-shaped and inverted U-shaped changes were observed in average temperature and air pollutants, respectively. The time lag of each variable was significant around nine days after exposure.

Conclusion: Using five MFAPs, the final model significantly predicted GERD-related medical utilization. In particular, PM_2.5 and CO were identified as risk or aggravating factors for GERD.

Keywords: Air pollution; Carbon monoxide; Gastroesophageal reflux disease; Meteorological factor; Particulate matter.

Figure 1

Granger causality test of the relationship between meteorological factors and air pollutants and GERD-related medical utilization. A: Various meteorological factors and air pollutants (MFAPs) show a direct or indirect association with GERD-related medical utilization; B: Relationship between the five selected MFAPs and GERD-related medical utilization. All variables were significantly correlated except AT and WS. The five selected MFAPs were significantly correlated to GERD-related medical utilization. MFAPs: Meteorological factors and air pollutants; GERD: Gastroesophageal reflux disease; WS: Wind speed; SD: Sunshine duration; AT: Average temperature; CO: Carbon monoxide; PM_2.5: Particulate matter with a diameter ≤ 2.5 µm.

Figure 2

Prediction model of gastroesophageal reflux disease -related medical utilization using a univariate generalized additive Poisson regression model. A: Gastroesophageal reflux disease (GERD)-related medical utilizations with AT; B: GERD-related medical utilizations as with particulate matter with a diameter ≤ 2.5 µm levels ≤ 40 μg/m³; C: GERD-related medical utilizations in the range of the IQR for carbon monoxide. CO: Carbon monoxide; PM_2.5: Particulate matter with a diameter ≤ 2.5 µm; ppm: Parts-per-million.

Figure 3

Time lag for exposure in multivariate analyses. A: Excess risk was significant after exposure up until 8 d for average temperature; B: Excess risk was significant after exposure up until 9 d for wind speed; C: Excess risk was significant after exposure up until 6 d for sunshine duration; D: Excess risk was significant after exposure up until 9 d for particulate matter with a diameter ≤ 2.5 µm; E: Excess risk was significant after exposure up until 9 d for carbon monoxide. ^aP < 0.05. CO: Carbon monoxide; PM_2.5: Particulate matter with a diameter ≤ 2.5 µm; ppm: Parts-per-million.

Figure 4

Three-dimensional graph of the prediction model. Each graph shows excess risk according to factor and time lag. A: Average temperature; B: Wind speed; C: Sunshine duration; D: Particulate matter with a diameter ≤ 2.5 µm; E: Carbon monoxide. CO: Carbon monoxide; PM_2.5: Particulate matter with a diameter ≤ 2.5 µm; ppm: Parts-per-million.