Mail-based Stool Collection in Women with and without Age-Related Macular Degeneration (AMD)

Abstract

Purpose : To demonstrate the feasibility of collecting stool samples via the mail for subsequent sequencing of the gut microbial DNA in relation to AMD status. We also explored response rates by AMD status.

Methods : From June to August 2017, 200 participants of the Carotenoids in Age-Related Eye Disease Follow-up Study (CAREDS2), an ancillary study of the Women’s Health Initiative (WHI), were mailed recruitment letters and consent/decline forms asking them to participate in a pilot study. Participants were recruited from random samples of CAREDS2 participants at participating clinic centers (Madison, WI; Iowa City, IA; Portland, OR). Women who returned signed consent forms via the mail were sent stool collection kits. Completed kits were mailed back to study personnel. Ten percent of mailed kits invited women to complete two stool collections from the same bowel movement (duplicates).

Results : Of the 200 women contacted, 152 (76%) consented via the mail. Kits were only sent to 150 women due to budget restrictions. There were 38 (19%) women who indicated they were not interested (n=22 mail; n=16 phone); 5 (3%) unable to be engaged or reached for participation; and 5 (3%) who indicated possible future interest. There were 142 (95%) women who returned kits; and 14 of these women sent duplicates (142 + 14=156 samples). Eleven (8%) of 142 women reported possible sample contamination (e.g., collection paper to catch stool ripped, stool was scrapped from toilet, or collected with an un-provided device), and 7 (4%) of 156 samples leaked in transit. One leaked sample could be replaced by a duplicate that did not leak. This provided samples from 125 women for sequencing, of which 92 had gradable fundus photographs for assessment of AMD. Response rate did not differ by AMD status (Table 1).

Conclusions : Collection of stool samples via the mail in postmenopausal women is feasible, both in women with and without AMD. Improvements in stool collection paper and reminders to tightly screw on the stool collection tube lid will likely improve usability of returned samples.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.