  BACKGROUND: Clinical factors influence surgery duration. This study also
investigated non-clinical effects. METHODS: 22 months of data about thoracic
operations in a large hospital in China were reviewed. Linear and nonlinear
regression models were used to predict the duration of the operations.
Interactions among predictors were also considered. RESULTS: Surgery duration
decreased with the number of operations a surgeon performed in a day (P<0.001).
Also, it was found that surgery duration decreased with the number of
operations allocated to an OR as long as there were no more than four surgeries
per day in the OR (P<0.001), but increased with the number of operations if it
was more than four (P<0.01). The duration of surgery was affected by its
position in a sequence of surgeries performed by a surgeon. In addition,
surgeons exhibited different patterns of the effects of surgery type for
surgeries in different positions in the day. CONCLUSIONS: Surgery duration was
affected not only by clinical effects but also some non-clinical effects.
Scheduling and allocation decisions significantly influenced surgery duration.
