Yu Andrew P, Wu Eric Q, Birnbaum Howard G, Emani Srinivas, Fay Madeleine, Pohl Gerhardt, Wintle Matthew, Yang Elaine, Oglesby Andalan
Analysis Group, Inc., Boston, MA 02199, USA.
Curr Med Res Opin. 2007 Sep;23(9):2157-69. doi: 10.1185/0300799007X219544.
Obesity is highly prevalent among patients with type 2 diabetes. Unfortunately, weight gain may also be a consequence of some antidiabetic medications. Although clinical benefits of weight loss have been established, the economic consequence of weight change among patients with type 2 diabetes is unclear.
The objective was to measure 1-year total and diabetes-related health care costs associated with weight change during the preceding 6-month period among type 2 diabetic patients on antidiabetic therapy.
Administrative claims, electronic laboratory data and medical chart information were abstracted for continuously enrolled adults with type 2 diabetes from an health maintenance organization (HMO) for the period from July 1, 1997 through October 31, 2005. To assess the economic impact of weight change, three regression models were applied to estimate the following: (1) the effect of weight change in general (one-slope model); (2) the different effects of weight gain and no weight gain (two-slope model); and (3) the different effects of weight gain and no weight gain (i.e., no change or weight loss) among obese and non-obese patients (four-slope model). Patients included in the study had a baseline weight measurement and a second weight measurement approximately 6 months later. They were also required to be on at least one antidiabetic drug therapy within 1 month around the baseline weight measurement date (index date). Based on the measured weight change, patients were classified into two groups--weight gainers and non-weight gainer. Total health care cost and diabetes-related cost were measured during the 1-year period following the second weight measurement and were adjusted to 2004 dollars by the medical component of the Consumer Price Index (CPI). Generalized linear models with log link function and gamma distribution were applied to assess the impacts of weight change on the 1-year total health care cost as well as 1-year diabetes-related cost. All models controlled for patients' baseline demographics, comorbidities, body mass index (BMI), glycosylated hemoglobin (HbA1c), and prior resource utilization.
The study included 458 patients, of whom 224 (48.9%) experienced minimum weight gain of 1 pound between the two weight measurements. The average 1-year total health care cost following the second weight measure was $6382 and the diabetes-related cost was $2002. The mean total health care cost was $7260 for the weight-gainers and $5541 for the non-weight gainers (p = 0.046), and the mean diabetes-related cost, respectively, was $2141 and $1869 (p = 0.006). Results from the models showed that one percentage point of weight change was positively associated with a 3.1% ($213, p < 0.01) change in total health care cost. When weight gain and no gain were modeled separately, one percentage point of weight loss was associated with a 3.6% ($256, p < 0.05) decrease in total health care cost and a 5.8% ($131, p < 0.01) decrease in diabetes-related cost. However, one percentage point of weight gain was not associated with significant increase in either total health care or diabetes-related cost. Further, results from the model with interactions between weight change and obesity status revealed that the economic benefit of weight loss was more pronounced in the obese group (BMI > or = 30). Log likelihood ratio tests showed that the one-slope model for total health care cost and the two-slope model for diabetes-related cost are the appropriate models of choice.
Weight loss significantly reduced diabetes-related costs. Controlling for baseline factors in the regression model, the 1-year total health care cost following 1% weight loss (or gain) was $213 cost decrease (or increase). Diabetes-related cost did not appear to be associated with weight gain. Economic benefit of weight loss was evident among type 2 diabetic patients on antidiabetic therapy, especially among obese patients.
肥胖在2型糖尿病患者中非常普遍。不幸的是，体重增加也可能是某些抗糖尿病药物的副作用。尽管体重减轻的临床益处已得到证实，但2型糖尿病患者体重变化的经济后果尚不清楚。
本研究旨在衡量接受抗糖尿病治疗的2型糖尿病患者在过去6个月内体重变化与1年总医疗费用及糖尿病相关医疗费用之间的关系。
从一家健康维护组织（HMO）中提取了1997年7月1日至2005年10月31日期间持续参保的成年2型糖尿病患者的行政索赔、电子实验室数据和病历信息。为评估体重变化的经济影响，应用了三个回归模型来估计：（1）总体重变化的影响（单斜率模型）；（2）体重增加和未增加的不同影响（双斜率模型）；（3）肥胖和非肥胖患者中体重增加和未增加（即无变化或体重减轻）的不同影响（四斜率模型）。纳入研究的患者在基线时进行了体重测量，大约6个月后进行了第二次体重测量。他们还被要求在基线体重测量日期（索引日期）前后1个月内至少接受一种抗糖尿病药物治疗。根据测量的体重变化，患者被分为两组——体重增加者和非体重增加者。在第二次体重测量后的1年内测量总医疗费用和糖尿病相关费用，并通过消费者价格指数（CPI）的医疗成分将其调整为2004年美元。应用具有对数链接函数和伽马分布的广义线性模型来评估体重变化对1年总医疗费用以及1年糖尿病相关费用的影响。所有模型均控制了患者的基线人口统计学特征、合并症、体重指数（BMI）、糖化血红蛋白（HbA1c）和先前的资源利用情况。
该研究共纳入458例患者，其中224例（48.9%）在两次体重测量之间体重至少增加了1磅。第二次体重测量后的平均1年总医疗费用为6382美元，糖尿病相关费用为2002美元。体重增加者的平均总医疗费用为7260美元，非体重增加者为5541美元（p = 0.046），糖尿病相关费用的平均值分别为2141美元和1869美元（p = 0.006）。模型结果显示，体重变化1个百分点与总医疗费用变化3.1%（213美元，p < 0.01）呈正相关。当分别对体重增加和未增加进行建模时，体重减轻1个百分点与总医疗费用降低3.6%（256美元，p < 0.05）以及糖尿病相关费用降低5.8%（131美元，p < 0.01）相关。然而，体重增加1个百分点与总医疗费用或糖尿病相关费用的显著增加无关。此外，体重变化与肥胖状态之间相互作用的模型结果显示，体重减轻的经济效益在肥胖组（BMI≥30）中更为明显。对数似然比检验表明，总医疗费用的单斜率模型和糖尿病相关费用的双斜率模型是合适的选择模型。
体重减轻显著降低了糖尿病相关费用。在回归模型中控制基线因素后，体重减轻（或增加）1%后的1年总医疗费用降低（或增加）213美元。糖尿病相关费用似乎与体重增加无关。在接受抗糖尿病治疗的2型糖尿病患者中，体重减轻的经济效益明显，尤其是在肥胖患者中。
