Читать книгу Randomised Clinical Trials - David Machin - Страница 23

Glaucoma Laser Trial Research Group (1995) recruited 271 subjects with newly diagnosed primary open‐angle glaucoma, and one eye of each patient was randomly assigned as initial treatment by argon laser (L) trabeculoplasty followed by Stepped (S) medication (LS). The other eye then received the treatments in reverse order, SL. They reported on the 261 eyes and found that measures of visual field status for eyes treated by the sequence LS were slightly better than those treated by SL. The authors’ state:

Statistical significance was attained for only some of the differences, and the clinical implications of such small differences are not known.

Key features include the following:

 Design: Multicentre, paired design, compares alternative schedules for administering two procedures – the schedule was randomised to one eye with the other eye receiving the alternative,

 Endpoint: Visual field status,

 Size: 271 patients with primary open‐angle glaucoma,

 Analysis: Comparison of means at particular time points following initiation of treatment using the paired t‐test,

 Conclusion: Eyes treated with laser trabeculoplasty first were slightly better than those eyes treated with topical medication first.