Meyer K, Breitschwerdt H, Kolling G H, Simonsz H J
Department of Medical Biometry, University of Heidelberg, Germany.
Br J Ophthalmol. 1998 Aug;82(8):934-8. doi: 10.1136/bjo.82.8.934.
The Early vs Late Infantile Strabismus Surgery Study Group investigates whether early or late surgery is preferable in infantile convergent strabismus, in a non-randomised, prospective, multicentre clinical trial. The current state of the study after end of recruitment is reported here, focusing on the question of possible sources for bias in this non-randomised trial.
The prognostic factors were analysed at baseline in order to check for imbalances between the two treatment groups. Reasons for possible differences are discussed.
There is no evidence for clinically relevant inhomogeneities between the two groups concerning the distribution of the three prognostic factors spherical equivalent, degree of amblyopia, and limitation of abduction. The fourth prognostic factor, horizontal angle of squint, differs significantly between the two groups.
In the analysis of the final results we may have to account for differences in angle of squint at baseline by its inclusion as a covariate or by stratification.
早期与晚期婴儿斜视手术研究组在一项非随机、前瞻性、多中心临床试验中，研究婴儿型内斜视早期手术还是晚期手术更可取。本文报告了招募结束后该研究的现状，重点关注这项非随机试验中可能存在偏差的来源问题。
在基线时分析预后因素，以检查两个治疗组之间是否存在不平衡。讨论了可能存在差异的原因。
关于三个预后因素等效球镜度、弱视程度和外展受限的分布，两组之间没有临床相关异质性的证据。第四个预后因素斜视水平角在两组之间有显著差异。
在最终结果分析中，我们可能需要将基线时的斜视角度差异作为协变量纳入或进行分层，以考虑该因素。
