Tijssen J G
Academic Medical Centre, Meibergdreef, The Netherlands.
Scand J Gastroenterol Suppl. 1999;231:15-9. doi: 10.1080/003655299750025228.
The Domestic/international Gastroenterology Surveillance Study (DIGEST) examined the prevalence of upper gastrointestinal symptoms among the general population in 10 countries, and the impact of these symptoms on healthcare usage and quality of life. This report discusses the validation of the DIGEST sample and reviews the response rates from the survey.
External validation of the DIGEST sample was conducted by comparing the age, age by gender and annual household incomes of the sample with census-derived data. A comparison was also made between Psychological General Well-Being Index (PGWBI) scores from study subjects in the Scandinavian countries and the USA and the total sample population norms.
Under- and oversampling, defined as > or =5% difference from the population norms, was evident in eight out of 10 countries, but no systematic bias was evident. The final distribution of the sample by gender was 51% female and 49% male. Although differences in PGWBI scores were noted between DIGEST subjects and population norms, these differences were <0.30 standard deviations--markedly below the difference considered as relevant for the PGWBI. Response for the survey in individual countries ranged from 17% in the USA to 61% in Norway, with a survey-wide rate of 27%. The overall response rate, including primary non-respondents, was 13.4%. The majority of nonresponse (51.4%) was attributed to failure to establish contact with the subjects, with 41.7% of subjects declining to be interviewed and the remaining 6.9% of subjects not meeting the age and sex criteria used for the survey.
The DIGEST sample exhibited good external validity, providing a foundation for comparison between data derived from individual countries in the survey.
国内/国际胃肠病学监测研究（DIGEST）调查了10个国家普通人群中上消化道症状的患病率，以及这些症状对医疗保健使用和生活质量的影响。本报告讨论了DIGEST样本的验证情况，并回顾了调查的应答率。
通过将样本的年龄、按性别划分的年龄以及家庭年收入与人口普查数据进行比较，对DIGEST样本进行外部验证。还比较了斯堪的纳维亚国家和美国的研究对象的心理总体幸福感指数（PGWBI）得分与总样本人群的标准值。
10个国家中有8个国家存在抽样不足和抽样过度的情况，即与人口标准值的差异≥5%，但未发现明显的系统偏差。样本按性别最终分布为女性5l%，男性49%。虽然DIGEST研究对象与人群标准值之间的PGWBI得分存在差异，但这些差异<0.30标准差，明显低于被认为与PGWBI相关的差异。各个国家的调查应答率从美国的17%到挪威的61%不等，全调查范围的应答率为27%。包括初次无应答者在内的总体应答率为13.4%。大多数无应答情况（51.4%）归因于未能与研究对象取得联系，41.7%的研究对象拒绝接受访谈，其余6.9%的研究对象不符合调查所使用的年龄和性别标准。
DIGEST样本具有良好的外部效度，为比较调查中各个国家的数据奠定了基础。
