Matson David O, Staat Mary Allen, Azimi Parvin, Itzler Robbin, Bernstein David I, Ward Richard L, Dahiya Ram, DiNubile Mark J, Barnes-Eley Myra, Berke Tamas
Graduate Program in Public Health, Eastern Virginia Medical School and Old Dominion University, Norfolk, VA 23501, USA.
J Paediatr Child Health. 2012 Aug;48(8):698-704. doi: 10.1111/j.1440-1754.2012.02445.x. Epub 2012 Apr 25.
The number of rotavirus hospitalisations is usually estimated from assigned diagnosis codes for gastroenteritis despite lack of validation for these indirect methods. Reliable estimates before and after introduction of vaccines are needed to quantify the absolute impact of new immunisation programs.
This 2-year study conducted at three hospitals prior to the licensure of the rotavirus vaccines in the USA compared two indirect methods for estimating hospitalisations for rotavirus gastroenteritis with estimates derived from prospective recruitment of children presenting with diarrhoea, vomiting or fever. For active surveillance, rotavirus gastroenteritis was confirmed by demonstration of stool antigen. The indirect residual and proportional methods assumed rotavirus to have caused a proportion of hospitalisations coded as acute gastroenteritis identified from computerised records.
There were 447 rotavirus hospitalisations among inpatients 31 days through 4 years of age admitted with vomiting and/or diarrhoea, compared with 306 and 228 hospitalisations identified by the two indirect methods. Only 52% of children hospitalised with gastroenteritis received a qualifying diagnosis code at discharge. Relative to active surveillance, the sensitivity and specificity (95% confidence interval (CI)) in identifying rotavirus-attributable hospitalisations was 45% (95% CI: 43-48%) and 89% (88-90%) for the residual method and 34% (30-39%) and 92% (90-94%) for the proportional method.
Many children admitted to the hospital with diarrhoea, vomiting or fever were not assigned discharge codes for acute gastroenteritis. Consequently, standard indirect methods missed a substantial number of rotavirus-associated hospitalisations, thereby underestimating the absolute number of children who could potentially benefit from vaccination.
尽管用于肠胃炎的指定诊断编码缺乏验证，但轮状病毒住院病例数通常是根据这些间接方法估算得出的。在引入疫苗前后都需要可靠的估算，以量化新免疫计划的绝对影响。
在美国轮状病毒疫苗获得许可之前，在三家医院开展的这项为期两年的研究，将两种估算轮状病毒肠胃炎住院病例数的间接方法与通过前瞻性招募出现腹泻、呕吐或发热症状的儿童得出的估算结果进行了比较。对于主动监测，通过粪便抗原检测确诊轮状病毒肠胃炎。间接残差法和比例法假定轮状病毒导致了一定比例的住院病例，这些病例被编码为从计算机记录中识别出的急性肠胃炎。
在因呕吐和/或腹泻入院的31天至4岁住院患者中，有447例轮状病毒住院病例，相比之下，两种间接方法识别出的住院病例数分别为306例和228例。因肠胃炎住院的儿童中，只有52%在出院时获得了符合条件的诊断编码。相对于主动监测，残差法识别轮状病毒所致住院病例的敏感性和特异性（95%置信区间（CI））分别为45%（95%CI：43 - 48%）和89%（88 - 90%），比例法的敏感性和特异性分别为34%（30 - 39%）和92%（90 - 94%）。
许多因腹泻、呕吐或发热入院的儿童在出院时未被分配急性肠胃炎的诊断编码。因此标准间接方法遗漏了大量与轮状病毒相关的住院病例，从而低估了可能从疫苗接种中受益的儿童绝对数量。
