Bharmal Murtuza F, Weiner Michael, Sands Laura P, Xu Huiping, Craig Bruce A, Thomas Joseph
Quintiles Strategic Research and Safety, Falls Church, VA, USA.
Alzheimer Dis Assoc Disord. 2007 Apr-Jun;21(2):92-100. doi: 10.1097/WAD.0b013e31805c0835.
This study estimated the prevalence of diagnosed dementia among Indiana Medicaid beneficiaries in 2004. The dependence of prevalence estimates upon use of several patient selection criteria to identify patients with dementia also was evaluated.
Indiana Medicaid claims data were analyzed for the period July 1, 2002 to December 31, 2004. An expert panel survey was conducted to assess perceived specificity of ICD codes used in previous studies to define dementia. Prevalence estimates were calculated with varying levels of each selection criteria, that is, ICD code set, interval of data examined, and number of occurrences of dementia-related claims. To assess specificity and sensitivity of the dementia patient selection criteria, Minimum Data Set data for a subset of beneficiaries that resided in a nursing home any time in 2004 were examined.
Depending on the patient selection criteria used, estimates of prevalence of diagnosed dementia for individuals 40 years old or older varied from 7.7% to 15.3%, whereas prevalence estimates for individuals 60 years old or older varied from 14.5% to 26.6%. When the following selection criteria were used: (1) occurrence of one or more dementia-related claims, (2) the expert panel ICD set, and (3) up to 30 months of data for defining dementia, the prevalence estimates in the Indiana Medicaid population were 10.9% for individuals 40 years old or older and 20.3% for individuals 60 years old or older.
Careful selection of claims-based criteria for identifying patients with dementia is important because the criteria may affect estimates by 100%. Prevalence of diagnosed dementia among Indiana Medicaid beneficiaries was 3 to 4 times higher than the reported prevalence from a decade ago in Medicaid populations of other states, even when the same patient selection criteria were used. A number of factors beyond increased occurrence of the disease including increased screening, greater likelihood of recording dementia codes in claims, or other factors may be responsible. The combination of patient selection criteria used in this study had good sensitivity, specificity, and accuracy when compared with Minimum Data Set data.
本研究估算了2004年印第安纳州医疗补助受益人中已确诊痴呆症的患病率。同时还评估了患病率估算对使用多种患者选择标准来识别痴呆症患者的依赖性。
对2002年7月1日至2004年12月31日期间印第安纳州医疗补助索赔数据进行了分析。开展了一项专家小组调查，以评估先前研究中用于定义痴呆症的国际疾病分类（ICD）编码的感知特异性。采用不同水平的每种选择标准计算患病率估算值，即ICD编码集、所检查数据的时间间隔以及与痴呆症相关索赔的出现次数。为评估痴呆症患者选择标准的特异性和敏感性，对2004年任何时间居住在疗养院的一部分受益人的最低数据集数据进行了检查。
根据所使用的患者选择标准，40岁及以上个体的已确诊痴呆症患病率估算值在7.7%至15.3%之间，而60岁及以上个体的患病率估算值在14.5%至26.6%之间。当使用以下选择标准时：（1）出现一项或多项与痴呆症相关的索赔；（2）专家小组ICD编码集；（3）用于定义痴呆症的最长30个月的数据，印第安纳州医疗补助人群中40岁及以上个体的患病率估算值为10.9%，60岁及以上个体为20.3%。
谨慎选择基于索赔的痴呆症患者识别标准很重要，因为这些标准可能使估算值相差100%。印第安纳州医疗补助受益人中已确诊痴呆症的患病率比其他州医疗补助人群十年前报告的患病率高出3至4倍，即便使用相同的患者选择标准也是如此。除了疾病发生率增加之外，还有许多因素可能导致这种情况，包括筛查增加、在索赔中记录痴呆症编码的可能性更大或其他因素。与最低数据集数据相比，本研究中使用的患者选择标准组合具有良好的敏感性、特异性和准确性。
