Limitations
trauma
SAID
This study serves as an initial feasibility trial, and thus carries limitations within the study design in terms of size, scope, and generalizability. Given that this was a preliminary study, the sample size was not powered to determine an effect size for outcomes. Thus, the clinical significance of results must be cautiously interpreted. In terms of generalizability, it is important to consider the demographic and patient profile of this study, and that the results are likely not relevant to higher-income country settings. It is possible that our participant population does not fully reach individuals in the lowest income categories since participants included in this study must have mobile phone access, and the financial resources and ability to reach ED. That said, this is a pragmatic trial at a regional trauma center where free referrals from other public clinics and free care can be provided, and is intended to serve as a proof of concept pragmatic effectiveness trial. We found exceptionally high rates of patient and provider acceptability of the PPKAY and SMS messages. It is important to note, however, that response bias is possible given that interviews were conducted by the study PI, the research nursing staff’s employer. In an attempt to address this potential bias, nursing staff were asked directly about the specific barriers they faced during enrollment, randomization, and follow-up stages.