Department of Community Dentistry, University of Oslo, Oslo, Norway.
BMC Health Serv Res. 2011 Oct 12;11:267. doi: 10.1186/1472-6963-11-267.
There has been a marked increase in the number of Caesarean sections in many countries during the last decades. In several countries, Caesarean sections are carried out in more than 20 per cent of births. These high Caesarean section rates give cause for concern, both from an economic and a medical perspective. A general opinion among epidemiologists is that the increase in the number of Caesarean sections during the last decade has been greater than could be expected in relation to medical risk factors. Therefore, other explanations must be sought. We studied one potential explanation; the effect that the increase in hospital revenue per bed during the period 1976-2005 has had on the Caesarean section rate in Norway. During this period, hospital revenue increased by about 260% (adjusted for inflation).
The analyses were carried out using data from the Medical Birth Registry 1976-2005 from Norway. The data were merged with data about hospital revenue, which were obtained from Statistics Norway. The analyses were carried out using annual data from 46 hospitals. A fixed effect regression model was estimated. Relevant medical control variables were included.
The elasticity of the Caesarean section rate with respect to hospital revenue per bed was 0.13 (p < 0.05). This represents an increase in the Caesarean section rate from the basis year 1976 to the final year 2005 of about 35 per cent. Most of the variables measuring characteristics of the health status of the mother and child had the expected effects.
The increase in hospital revenue explains only a small part of the increase in the Caesarean section rate in Norway during the last three decades. The increase in the Caesarean section rate is considerably greater than could be expected, based on the increase in hospital revenue alone. The strength of our study is that we have estimated a cause and effect relationship. This was done by using fixed effects for hospitals, a lagged revenue variable and by including an extensive set of control variables for the risk factors of the mother and the baby.
在过去几十年中，许多国家的剖宫产数量显著增加。在一些国家，剖宫产率超过 20%。这些高剖宫产率引起了关注，无论是从经济角度还是医学角度来看。流行病学家的普遍观点是，过去十年中剖宫产数量的增加超过了与医疗风险因素相关的预期。因此，必须寻找其他解释。我们研究了一个潜在的解释；1976 年至 2005 年期间，医院每张床位收入的增加对挪威剖宫产率的影响。在此期间，医院收入增长了约 260%（经通胀调整）。
使用挪威 1976 年至 2005 年的医疗出生登记处的数据进行分析。将数据与从挪威统计局获得的有关医院收入的数据合并。使用来自 46 家医院的年度数据进行分析。估计了固定效应回归模型。纳入了相关的医疗控制变量。
每张床位医院收入的剖宫产率弹性为 0.13（p < 0.05）。这代表从基础年 1976 年到最终年 2005 年，剖宫产率增加了约 35%。大多数衡量母婴健康状况特征的变量都具有预期的效果。
在过去三十年中，医院收入的增加仅解释了挪威剖宫产率增加的一小部分。仅根据医院收入的增加，剖宫产率的增加幅度就大大超过了预期。我们研究的优势在于，我们估计了因果关系。这是通过对医院使用固定效应、滞后的收入变量以及纳入广泛的母婴风险因素控制变量来实现的。
