Telephone interviews and online questionnaires can be used to improve neurodevelopmental follow-up rates.

BACKGROUND

Maximising response rates to neurodevelopmental follow-up is a key challenge for paediatric researchers. We have investigated the use of telephone interviews and online questionnaires to improve response rates, reduce non-response bias, maintain data completeness and produce unbiased outcomes compared with postal questionnaires when assessing neurodevelopmental outcomes at 2 years.

METHODS

A prospective cohort study of babies born ≥32 weeks gestation. Neurodevelopmental outcomes were assessed at 2 years of age using a parent questionnaire completed via post, telephone or online. Relative Risks with 95% confidence intervals (RR; 95% CI) were calculated to identify participant characteristics associated with non-response and questionnaire response mode (postal vs. telephone/online). The proportion of missing data and prevalence of adverse outcomes was compared between response modes using generalized linear models.

RESULTS

Offering telephone/online questionnaires increased the study response rate from 55% to 60%. Telephone/online responders were more likely to be non-white (RR 1.6; [95% CI 1.1, 2.4]), non-English speaking (1.6; [1.0, 2.6]) or have a multiple birth (1.6; [1.1, 2.3]) than postal responders. There were no significant differences in the prevalence of adverse neurodevelopmental outcomes between those who responded via post vs. telephone/online (1.1; [0.9, 1.4]). Where parents attempted all questionnaire sections, there were no significant differences in the proportion of missing data between response modes.

CONCLUSIONS

Where there is sufficient technology and resources, offering telephone interviews and online questionnaires can enhance response rates and improve sample representation to neurodevelopmental follow-up, whilst maintaining data completeness and unbiased outcomes.