健康資本與產前檢查:以SARS對孕婦影響為例

Abstract

為了保障孕婦和胎兒健康，健保每年花費約十億，提供每位孕婦十次免費產前檢查。 雖說過去研究均證實產前檢查能提升胎兒健康，但因產檢時間和數目均為內生決定，免 費產檢成效仍為一個待回答的研究議題。本研究主要分析產檢和對產婦和嬰兒健康間的 因果關係。未來克服產檢的內生性，我們利用台灣於2003 年所發生嚴重急性呼吸道疾 病(即SARS)疫情。基於SARS 的不確定性，許多產婦被迫放棄或延後產檢，造成孕婦 平均產檢數目由2002 年的9.5 次下降至2004 年的8.1 次，這個外生衝擊所產檢數目下 降，提供一個管道來分析產檢對產婦生產和嬰兒健康的因果影響。在第一年度計畫中， 我們預計使用2002-2006 年婦女生產前一年的門診資料，採差異中的差異法，確立SARS 對孕婦選擇醫療院和產檢時間和次數間關係。由於SARS 疫情存在明顯地域差別，在第 二年的計畫中，我們計畫進一步串連婦女和嬰兒資料，以地區和時間為工具變數，採工 具變數法分析產檢能否改善婦女生產(流產和剖腹產)和胎兒健康(早產、五歲前醫療費用、 疾病類別)。

To enhance the health of pregnant women and babies, National Health Insurance spends about NT 1 billion each year to provide the prenatal care through ten free prenatal visits. Despite that the existing literature confirmed the benefits of prenatal care, the efficacy of these prenatal visits remains unclear since the number and timing of visits are endogenously determined. In this project, we aim to analyze the causal effect of prenatal care on the health of babies and mothers. To overcome the endogeneity of these visits, we employ an epidemic incident---the outbreak of Severe Acute Respiratory Syndrome (SARS) in Taiwan in 2003. In light of uncertainty associated with SARS, a substantial number of pregnant women decided to postpone or cancel scheduled visits, resulting in a reduction of the average number of prenatal visits from 9.5 in 2002 to 8.1 in 2004. This exogenous reduction in prenatal visits due to SARS provides an excellent opportunity to analyze the causal benefits of prenatal care. With the help of outpatient records of women giving births between 2002 and 2006, the first year’s project plans to use the difference-in-differences method to identify the impact of SARS on the choice of health providers, as well as timing and the number of prenatal visits. Given the SARS cases concentrates in Taipei area, the second year’s project plans to combine the inpatient and outpatient files of mothers and babies, and employ the instrument variable method (geographic variations as instruments) to sort out the causal effect of mother’s health (in terms of abortions and cesarean section) and baby’s health (in terms of premature birth, infant mortality, types of illnesses, and medical expenses within the first five years).