Publicly funded interfacility ambulance transfers for surgical and obstetrical conditions: A cross sectional analysis in an urban middle-income country setting

Introduction Interfacility transfers may reflect a time delay of definitive surgical care, but few studies have examined the prevalence of interfacility transfers in the urban low- and middle-income (LMIC) setting. The aim of this study was to determine the number of interfacility transfers required for surgical and obstetric conditions in an urban MIC setting to better understand access to definitive surgical care among LMIC patients. Methods A retrospective analysis of public interfacility transfer records was conducted from April 2015 to April 2016 in Cali, Colombia. Data were obtained from the single municipal ambulance agency providing publicly funded ambulance transfers in the city. Interfacility transfers were defined as any patient transfer between two healthcare facilities. We identified the number of transfers for patients with surgical conditions and categorized transfers based on patient ICD-9-CM codes. We compared surgical transfers from public vs. private healthcare facilities by condition type (surgical, obstetric, nonsurgical), transferring physician specialty, and transfer acuity (code blue, emergent, urgent and nonurgent) using logistic regression. Results 31,659 patient transports occurred over the 13-month study period. 22250 (70.2%) of all transfers were interfacility transfers and 7777 (35%) of transfers were for patients with surgical conditions with an additional 2,244 (10.3%) for obstetric conditions. 49% (8660/17675) of interfacility transfers from public hospitals were for surgical and obstetric conditions vs 32% (1466/4580) for private facilities (P<0.001). The most common surgical conditions requiring interfacility transfer were fractures (1,227, 5.4%), appendicitis (913, 4.1%), wounds (871, 3.9%), abdominal pain (818, 3.6%), trauma (652, 2.9%), and acute abdomen (271, 1.2%). Conclusion Surgical and obstetric conditions account for nearly half of all urban interfacility ambulance transfers. The most common reasons for transfer are basic surgical conditions with public healthcare facilities transferring a greater proportion of patient with surgical conditions than private facilities. Timely access to an initial healthcare facility may not be a reliable surrogate of definitive surgical care given the substantial need for interfacility transfers.

This work represents an international collaboration between academic partners in the United States and Colombia as well as government sector involvement to evaluate the role and scope of surgical disease among interfacility ambulance transfers in the middle-income country setting. The manuscript is based on an analysis of primary data from the publicly funded ambulance system, Salud Centro, with the aim to determine the number of interfacility transfers due to surgical and obstetric conditions in an urban MIC setting to better understand access to definitive surgical care among MIC patients.
The manuscript sheds light on the systems levels strain that untreated surgical disease has on the p blic heal h s s em and con e ali es his i hin Colombia s heal hcare service framework. Our work fits within the timeliness domain outlined by the Lancet Commission on Global Surgery as we investigate systems level delays in surgical healthcare access in the MIC setting. Ultimately, we have shown that surgical conditions make up a significant proportion of all interfacility ambulance transfers in Cali Colombia suggesting that even in the urban middleincome country setting, there is need for policy implementation towards improving access to timely and definitive surgical healthcare for the population. We believe this manuscript aligns with the aims of PLOS One and will be of benefit to surgeons working in the measurement of the public healthcare sector in low-and middle-income countries across the world.
This manuscript represents original work and has not been published or under consideration for publication in any other journals. We look forward to the opportunity to publish our results and further inform the field of academic global surgery and surgical system science.
Sincerely,     The fact that the most common conditions being transferred by the public sector in our 255 study were largely surgical may reflect a system that varies in infrastructure and workforce 256 capacity key to delivering both timely and definitive surgical healthcare. Importantly, it is not 257 known whether interfacility transfer is a solution to, or an outcome of the vertical integration 258 suggested to be present in Colombia. 30 Further data surrounding the interface between 259 vertically independent healthcare entities is needed to understand how to best utilize the limited 260 Although some hospitals utilizing the public EMS agency were utilized in our analysis, 284 this study does not account for the private ambulances operated by the individual hospitals. 285 Such a large selection bias requires a collaborative cross-agency study to overcome these 286 limitations of our study design. Finally, this study does not take into account the formal and 287 informal transfer agreements that may exist because of contractual commitments between 288 primary and secondary healthcare facilities, the public EMS agency, and local workforce, 289 governance and finance infrastructures. Therefore, many non-clinical and confounding variables 290 exist with regard to why the secondary hospitals may be more inclined to accept the volume of 291 interfacility transfers exhibited in this study. 292

Conclusion 293
Surgical and obstetric conditions account for over half of all interfacility ambulance 294 transfers in this urban MIC setting. The most common reasons for transfer are basic surgical 295 conditions, with public healthcare facilities requiring a greater proportion of interfacility transfers 296 for surgical conditions. Further research towards the nature of hospital interface through 297 prehospital transfers is needed to understand how to best utilize the limited surgical workforce 298 and infrastructure in middle income century. Nevertheless, a foundation for additional research 299 could you identify some recommendations or priorities for the regional vocation in accordance or not with the WHO guidelines or others?