The original TITCO cohort includes data on 16 000 patients admitted to four public university hospitals in urban India. At the time of the research Jai Prakash Narayan Apex Trauma Center (JPNATC), All India Institute of Medical Sciences, New Delhi, was a dedicated trauma centre with almost 180 beds. King Edward Memorial hospital (KEM), Mumbai, was a tertiary level hospital with no dedicated trauma ward. Lokmanya Tilak Municipal General Hospital (LTMGH), Mumbai was a tertiary level public university hospital with a dedicated trauma ward with 14 beds. The Institute of Post-Graduate Medical Education and Research and Seth Sukhlal Karnani Memorial Hospital (SSKM), Kolkata was a tertiary level public university hospital, but without a dedicated trauma ward. The cost of care in these hospitals was nominal and the patients admitted represented mainly a lower socioeconomic stratum of the population. The first patient was enrolled in July 2013 and the last patient in December 2015. The exact enrollment period varied across participating hospitals.
One dedicated project officer collected data on site for approximately eight hours, five days per week. The shifts were rotated, so that the project officers worked morning, evening, and night shifts, and then had a day off. This way all possible shifts were covered during the course of a month. Data for patients arriving during the project officers shifts were collected by direct observation in the area where trauma patients were received, and the project officers were allowed to ask the health care staff for values of parameters not entered into the patient's records. For example, if the systolic blood pressure was measured (the project officer could see it being measured) but was not documented in the patient record, the project officer was allowed to ask for its value. Data for patients arriving to hospital outside the project officers' shifts were recorded from patient records. These patients were identified from the nurses' log books in the emergency department.
Patients of all ages were included if they presented with history of trauma and were admitted or died between arrival and admission. Patients with isolated limb injury and patients who were dead on arrival were not included.
We obtained ethical approval for the collection of data for the original research from each of the participating hospitals. The names of the ethical bodies and reference numbers were Institute Ethics Committee All India Institute of Medical Sciences (EC/NP-279/2013 RP-Ol/2013), Institutional Ethics Committee (IEC(I)/OUT/222/14), Ethics Committee of the Staff and Research Society (IEC/11/13), and IPGME&R Research Oversight Committee (IEC/279) for JPNATC, KEM, LTMGH, and SSKM respectively. We applied for a waiver of informed consent, which was granted by all review boards. The patients included in this study were all admitted after trauma, often arriving with an altered level of consciousness and in severe physical and psychological distress. As the original research involved only collection of routine data and did not alter the care provided in any way, we and the ethics committees felt that obtaining informed consent would be to burden the patients or their relatives unnecessarily. Names, addresses, telephone, social security or insurance numbers were never collected.