World Health Information Science Consultants, LLC, Newton, MA 02466, USA.
Pharmacoepidemiol Drug Saf. 2011 Nov;20(11):1159-67. doi: 10.1002/pds.2249. Epub 2011 Sep 16.
Studies based on the first appearance of a code for esophageal cancer in the General Practice Research Database (GPRD) have yielded conflicting results concerning the relationship between disease onset and prior bisphosphonate use. The literature on the timing of cancer code appearance in general practice records is scanty but suggests that there may be substantial error by comparison with actual dates of clinical onset.
To assess the accuracy of codes for esophageal cancer in the GPRD and to determine whether it was possible to infer clinical date of onset.
A reviewer adjudicated the records of women with codes for esophageal cancer from 1996 to 2008 by using chronological GPRD listings of codes for diagnoses, services, and tests. GPRD staff sought reviews by the general practices for 75 women whom the reviewer classified as having esophageal cancer and 25 classified as not having the condition.
Essentially all cases bearing a code for the condition had esophageal cancer. Where data were available to permit dating of clinical onset (75% of cases), the result agreed with the date recorded in the clinical record to within 60 days in 89% of cases. The remaining 25% of cases had little or no clinical information and could not be dated. Clinical onset preceded the first appearance of a cancer code by more than 6 months in 10% of cases.
The accurate timing of clinical onset and diagnosis in the GPRD, at least of esophageal cancer in women, may require the review of clinical records or future linkage to cancer registries.
基于普通科实践研究资料库（GPRD）中食管癌首次出现代码的研究结果，有关疾病发病与先前使用双膦酸盐之间的关系存在矛盾。关于一般实践记录中癌症代码出现时间的文献很少，但表明与实际临床发病日期相比，可能存在大量错误。
评估 GPRD 中食管癌代码的准确性，并确定是否有可能推断临床发病日期。
通过使用 GPRD 中按时间顺序列出的诊断、服务和检查代码，由一名审核员对 1996 年至 2008 年间患有食管癌代码的女性记录进行审核。GPRD 工作人员为审核员分类为患有食管癌的 75 名女性和分类为未患有该疾病的 25 名女性的一般实践寻求审核。
基本上所有带有该疾病代码的病例都患有食管癌。在可以确定临床发病日期的情况下（75%的病例），结果与临床记录中记录的日期相差 60 天以内的病例占 89%。其余 25%的病例几乎没有或没有临床信息，无法进行日期确定。在 10%的病例中，临床发病早于癌症代码首次出现超过 6 个月。
在 GPRD 中，至少在女性中，临床发病和诊断的准确时间可能需要审核临床记录或未来与癌症登记处的链接。
