百万女性乳腺癌筛查研究发现体重指数影响住院费用
根据世界卫生组织（WHO）的定义，体重指数≥25kg/m²为超重，≥30kg/m²为肥胖。虽然超重与健康状况不佳、医疗费用增加有相关性，但是超重对住院总费用和不同健康状况费用的具体影响尚不明确。
2017年4月5日，英国《柳叶刀公共卫生学分册》在线发表牛津大学的百万女性研究报告，发现体重指数影响住院费用。
该前瞻队列研究由英国癌症研究中心、英国医学研究理事会、英国国家卫生研究院资助，于1996～2001年从国家医疗服务（NHS）的60个乳腺癌筛查中心入组119万8393位50～64岁英格兰女性进行随访，估算2006年4月1日～2011年3月31日每年的住院费用和入院率，并记录研究入组时的体重指数、按照国际疾病分类第10版（ICD-10）定义的主要入院诊断。最后，将体重指数与住院费用的相关性，按2013年英格兰所有55～79岁女性人口估计每年住院总费用。
结果共有109万3866位女性提供了身高和体重信息，体重指数≥18.5kg/m²，入组时无癌症病史，自2006年4月1日起平均随访4.9年（入组后12.3年），期间记录到入院184万次。
体重指数为20.0～22.5kg/m²的女性每年住院费用最低，每位女性每年567英镑（99%置信区间：556～577英镑）。
体重指数＞20kg/m²后，每增加2kg/m²，每年住院费用增加7.4%（99%置信区间：7.1%～7.6%）。
超重与所有疾病诊断分类的费用增加有相关性，除了呼吸系统疾病和骨折。
在英格兰所有55～79岁的女性中，估计每年住院总费用45亿英镑的6.62亿英镑（14.6%）由于超重，其中5.17亿英镑（78%）由于入院手术、2.58亿英镑（39%）由于肌肉骨骼问题入院，主要为膝关节置换手术。
因此，超重与英格兰中老年女性各种情况（尤其是膝关节置换手术和糖尿病）的住院费用增加有相关性，这些结果对超重医疗费用提供了可靠的最新估计，并强调需要进行投入以解决这个公共卫生问题。
对此，伦敦大学卫生与热带医学院、牛津大学发表同期述评：超重的代价。
Lancet Public Health. 2017 Apr 5. [Epub ahead of print]
Hospital costs in relation to body-mass index in 1.1 million women in England: a prospective cohort study.
Seamus Kent, Jane Green, Gillian Reeves, Valerie Beral, Alastair Gray, Susan A Jebb, Benjamin J Cairns, Borislava Mihaylova; on behalf of the Million Women Study collaborators.
University of Oxford, Oxford, UK.
Background: Excess weight is associated with poor health and increased health-care costs. However, a detailed understanding of the effects of excess weight on total hospital costs and costs for different health conditions is needed.
Methods: Women in England aged 50-64 years were recruited into the prospective Million Women Study cohort in 1996-2001 through 60 NHS breast cancer screening centres. Participants were followed up and annual hospital costs and admission rates were estimated for April 1, 2006, to March 31, 2011, in relation to body-mass index (BMI) at recruitment, overall and for categories of health conditions defined by the International Classification of Diseases 10th revision chapter of the primary diagnosis at admission. Associations of BMI with hospital costs were projected to the 2013 population of women aged 55-79 years in England.
Findings: 1093866 women who provided information on height and weight, had a BMI of at least 18.5 kg/m², and had no previous cancer at recruitment, were followed up for an average of 4.9 years from April 1, 2006 (12.3 years from recruitment), during which time 1.84 million hospital admissions were recorded. Annual hospital costs were lowest for women with a BMI of 20.0 kg/m² to less than 22.5 kg/m² (£567 per woman per year, 99% CI 556-577). Every 2 kg/m² increase in BMI above 20 kg/m² was associated with a 7.4% (7.1-7.6) increase in annual hospital costs. Excess weight was associated with increased costs for all diagnostic categories, except respiratory conditions and fractures. £662 million (14.6%) of the estimated £4.5 billion of total annual hospital costs among all women aged 55-79 years in England was attributed to excess weight (BMI ≥25 kg/m²), of which £517 million (78%) arose from hospital admissions with procedures. £258 million (39%) of the costs attributed to excess weight were due to musculoskeletal admissions, mainly for knee replacement surgeries.
Interpretation: Excess body weight is associated with increased hospital costs for middle-aged and older women in England across a broad range of conditions, especially knee replacement surgery and diabetes. These results provide reliable up-to-date estimates of the health-care costs of excess weight and emphasise the need for investment to tackle this public health issue.
Funding: Cancer Research UK; Medical Research Council; National Institute for Health Research.
DOI: 10.1016/S2468-2667(17)30062-2
Lancet Public Health. 2017 Apr 5. [Epub ahead of print]
The costs of overweight.
W Philip T James, Klim McPherson.
London School of Hygiene & Tropical Medicine, London, UK; University of Oxford, Oxford, UK.
DOI: 10.1016/S2468-2667(17)30068-3