Difficulties in developmental follow-up of preterm neonates in a randomised-controlled trial of Bifidobacterium breve M16-V - Experience from Western Australia.

BACKGROUND: Probiotics may be neuroprotective for preterm neonates due to their anti-inflammatory effects and ability to facilitate nutrition. AIM: To assess long-term effects of early probiotic supplementation on neuropsychological development in preterm infants. STUDY DESIGN: Follow up study. SUBJECTS: Children at age 3 to 5 years who had participated as preterm infants (<33 week) in the randomised controlled trial. OUTCOMES: Primary: Continuous early learning composite measure derived from the Mullen's Scale of Early Learning (MSEL). Other outcomes were assessed by the Developmental, Dimensional and Diagnostic Interview, Developmental NEuroPSYchological assessment-2nd Edition, Parental questionnaires using children's communication checklist-2nd edition, social responsiveness scale, and Vineland Adaptive Behavioural Scales-2nd edition. MEASURES: Continuous scores derived from all the measures. RESULTS: 67 children of the 159 participants (42%) (Probiotic: 36/79, Placebo: 31/80) were followed-up for at least one neuropsychological assessment. All six assessments were completed in 18/31 (58.1%) of the control vs. 11/36 (30.6%) probiotic group children. Multivariable analysis of MSEL composite score showed no evidence of probiotic effect univariately, or after adjustment for gestation, intrauterine growth restriction, Apgar <7 at 5 min and age at assessment (adjusted mean effect in probiotic group: -2.7, 95% CI -8.5-3.0, p = 0.349). CONCLUSION: There was no significant effect on neurodevelopment of children assessed at the age of 3 to 5 years who participated as preterm neonates in the RCT of B. breve M-16V. The validity of these results is limited by the reduced sample size due to high rate of loss to follow up.

Introductory postcards: do they increase response rate in a telephone survey of older persons?

The purpose of this study was to assess whether contact by mail via an introductory postcard would increase the response rate to a telephone survey in a selected population of 348 people 60 years and older. Of this group, 208 were sent a postcard introducing the study and informing them that someone would call in the next 1-2 weeks to conduct a telephone interview. The remaining sample of 140 did not receive the introductory postcard. Amongst the potential participants who were contacted and able to participate (n = 240), the response rate for completed interview was 58.0% for those sent a postcard and 42.3% for those who were not. The refusal rate was 25.3% (postcard sent) and 37.2% (not sent a postcard). When the outcome of contact is collapsed to two categories, 'agreed to participate' and 'refusal', the response rate to participate was 73.5% (sent a postcard) and 59.0% (not sent a postcard) (chi(2) 5.14, d.f. 1, sign. 0.023). The response rate amongst those who recall being sent a postcard rose to 86.0%. Whether agreeing to participate or refusing to be involved in the survey was dependent on being sent an introductory postcard. The conclusion is that mailing a postcard prior to the first telephone contact increases the participation rates of older persons in a telephone survey at very little extra cost (A$0.60 per person).