Study setting and study design
We performed a cross-sectional study between June-August 2014 on 412 patients scheduled for elective surgery at the main operation theatre of Mulago hospital. The hospital has a capacity of 1500 beds, and acts both as a national referral hospital and a teaching hospital, serving 38 million Ugandans, as well as patients referred from neighboring countries. The hospital surgical unit has a total of 18 operating rooms, distributed amongst the different surgical departments  (Table 1). Two of these operation rooms are dedicated to emergency surgical operations. Of the remaining operation rooms, 4 are located at the respective surgical departments (E.N.T unit-1, Opthalomology unit-1, Orthopedic surgery unit-1, and Burns and reconstruction unit-1). The rest of the surgical operation rooms are located in the Main hospital theatre. All elective surgery operations are conducted from the respective operation theatres. In situations when the emergency theatre is overwhelmed, the pending emergency surgeries are transferred to the main theatre. The main hospital operation theatre operates 5 days a week (Monday to Friday) from 9:00 am to 5:00 pm. Approximately 20-30 surgical operations are conducted from the main operation theatre daily. The decision to operate a patient with a surgical condition is made by surgeons at the hospital surgical outpatients clinic. Here, a patient is assessed and assigned a future date when they are to report to the hospital for surgery. The Urgency for the operation is determined by the patients’ diagnosis, disease severity and availability of theatre space. In addition, patients who do not require surgery after presenting to the emergency department are also given a return date for admission for elective surgery at the hospital. Depending on the patients’ diagnosis, pre-surgical hospital admission and prepping is done at the respective surgical units (wards). Pre-operative prepping includes clinical and diagnostic assessment of the patient, as well as laboratory workup. When a decision to operate has been made, pre-transfusion blood samples are drawn for grouping and cross-matching of blood for patients for whom the attending surgeon anticipates the use of blood before, during, or after surgery. All the surgical wards except the private section use the main theater and have stipulated operation days. Except for patients admitted to the private section, surgical treatment is free at Mulago hospital. In a few instances however, a patient maybe requested to buy some materials for use during the surgery (e.g. bone fixation plates for orthopedic fractures) in case they are unavailable at the hospital.
Out of the 412 study subjects, 237 were admitted for elective surgery via the surgical outpatients’ clinic; the rest being admitted through the surgical emergency unit (Table 2). All patients scheduled for elective surgery at the main hospital theatre during the study period were enrolled in to the study. Patients scheduled for elective surgery in other elective operation theatres other than the main hospital operation theatre (e.g. the Obstetric and gynecology theatres, and the satellite operation theatres located on the surgical units) were excluded from the study. Consecutive sampling was used during enrolling of study subjects.
We defined time-to-surgery (waiting time-to-surgery) as the duration (in days) from when the diagnosis of the surgical condition was made by the admitting surgeon to the date the surgery was done.
Reason for rescheduling surgery
When a surgical operation was rescheduled to another day, the primary reason for the delay was determined and classified as: a) patient factors, b) health care provider factors or c) health care facility factors.
Patient factors for rescheduling of surgery included active medical problems such as infection, uncontrolled blood pressure, and cardiac problems like heart failure and arrhythmia. Reschedules due to health care provider factors were either due to a surgeon or anesthesiologist being absent for the operation, or due to inadequate preparation of a patient for surgery. Health care system factors included: lack of theatre space, lack of adequate supplies and equipment to carry out the surgery, lack of utilities, like water and electricity, lack of space (beds) in the intensive care unit, absence of blood for intra-operative or post-operative transfusion, and equipment break down.
Data were collected by retrospective chart review and face-to-face interviews using standardized, pretested forms. For each subject, age, sex, tribe, physical address, occupation, level of education, date of admission, diagnosis, planned surgical procedure, and the scheduled date for the operation were recorded. The patient was also interviewed to ascertain whether surgery was done or not. In the case of cancellation or postponement, a record of the reason was made.
Overall, there were over 150 different surgical diagnoses. During data analysis, these diagnoses were summarized by surgical specialty (detailed in supplementary information) in to; general surgery, orthopedic, neurosurgery, urology, Ear, Nose and Throat (E.N.T) surgery, ophthalmology, paediatric surgery, cardio-thoracic surgery, oral and maxillo-facial surgery, and plastic surgery. For the current study, the purpose of surgery was recorded as curative, diagnostic, reconstructive, or palliative. Written informed consent was sought from each study participant prior to enrollment, and approval to conduct the study was obtained from the Institutional review board of Mulago National referral hospital, and the School of Biomedical Sciences, College of Health Sciences, Makerere University.
We report both the mean±SD and median waiting time to surgery for participants in the current study. Descriptive values of categorical variables were computed as frequencies (count and percent). Kruskal-Wallis H test was used for comparison of differences among the categories of factors affecting median waiting time to surgery, followed by post-hoc Dunn’s test if the observed difference was statistically significant. An alpha level of 0.05 was used for all statistical tests. PASW (ver. 18) software was used for all statistical computation.