Dear Editor,

We are pleased to respond to the Letter to the Editor regarding our article, “Encrypted smartphone text messaging between spine surgeons may reduce after-hours surgery” [1]. The writers have presented several concerns regarding our work, many of which we believe have been acknowledged and addressed in the original manuscript.

With respect to the retrospective design of our study, we agree that a prospective study would have been superior and proposed such work in the final paragraph of the discussion.

We also share concerns regarding the generalizability of the data. In the discussion section of our article, we point out the limitations with regard to generalizability, due to our location at a Canadian center with relatively low after-hours volume. We would agree that a larger, multi-center design would be ideal for future work in this area.

The writers correctly identify that we used case length as a surrogate for complexity, without more detail. In our discussion, we identified this as a limitation, and in the final paragraph proposed further study with a higher degree of granularity to delineate these effects.

We also share concerns about digital security. Therefore, the discussion section included a detailed section about limiting privacy breeches on individual smartphones, turning off backups / cloud storage, anonymization of any information entered, and deletion of data once it is no longer used. We employed these strategies in implementing the CPMS platform with the spine service.

Cost-effectiveness was not addressed in our manuscript, as it was not the focus of the study. But frankly, there would be limited role for a cost-effectiveness analysis, as there was no cost to implementation of the CPMS platform. As such, any benefit shown by this technology has seemingly little drawback in terms of cost.

Finally, the writers had questions about the statistical methodology. As we shared in our methods section, we computed the monthly rate of surgical cases, surgical times, types of surgery, etc. and used these data to compute variance as well as perform statistical comparison using one-way ANOVA. For clarity, the month-to-month data were provided in databases from our Digital Health Analytics team, as referenced in the manuscript.

We thank the writers for their feedback on our article. We agree that the study has substantial limitations and would strongly encourage further study on this topic. We would encourage prospective, high-volume multi-center studies with more granular data for outcome and demographic analysis.