Evaluating the reliability, validity, acceptability, and practicality of SMS text messaging as a tool to collect research data: results from the Feeding Your Baby project

Objective To test the reliability, validity, acceptability, and practicality of short message service (SMS) messaging for collection of research data. Materials and methods The studies were carried out in a cohort of recently delivered women in Tayside, Scotland, UK, who were asked about their current infant feeding method and future feeding plans. Reliability was assessed by comparison of their responses to two SMS messages sent 1 day apart. Validity was assessed by comparison of their responses to text questions and the same question administered by phone 1 day later, by comparison with the same data collected from other sources, and by correlation with other related measures. Acceptability was evaluated using quantitative and qualitative questions, and practicality by analysis of a researcher log. Results Reliability of the factual SMS message gave perfect agreement. Reliabilities for the numerical question were reasonable, with kappa between 0.76 (95% CI 0.56 to 0.96) and 0.80 (95% CI 0.59 to 1.00). Validity for data compared with that collected by phone within 24 h (kappa = 0.92 (95% CI 0.84 to 1.00)) and with health visitor data (kappa = 0.85 (95% CI 0.73 to 0.97)) was excellent. Correlation validity between the text responses and other related demographic and clinical measures was as expected. Participants found the method a convenient and acceptable way of providing data. For researchers, SMS text messaging provided an easy and functional method of gathering a large volume of data. Conclusion In this sample and for these questions, SMS was a reliable and valid method for capturing research data.