The comparison of objective OR times of residents and specialists showed significant differences for various types of surgeries (tables 1 and 2). There was a significant difference in surgical post processing time after the extirpation of a cervical lymph node between residents and specialists (p = 0.006), with residents taking significantly more time. Time between the patient`s and the surgeon`s entrance into the operating room was somewhat longer for the residents (p=0.030).
Comparing the OR times of panendoscopy including microlaryngoscopy, significant time discrepancies between residents and specialists could be ascertained for the time between the surgeon’s entrance and the patient’s entrance into the operating room (p= 0.007). Differences were also observed in surgical preparation time (p<0.001), incision to suture time (p<0.0001), post-processing time (p=0.025), entire operating room time (p=0.001), entire duration of surgical action (p= 0.012) and the sum of incision to suture time and time of surgical action (p<0.0001).
Except for arrival time to the OR and post-processing time, durations of specialists were significantly shorter than those of residents.
Regarding sinus surgery, the study revealed significant time differences regarding the time between entering of the surgeon and patient in the OR (p=0.018), incision to suture time (p<0.0001), entire OR time (p<0.0001) and the sum of incision to suture and surgical preparation and post-processing time (p<0.0001). As before, residents were more on schedule when they entered the operating room, but they operated slower than the specialists.
The comparison of time required by residents and specialists performing nasal septoplasty showed significant disparity concerning the time between the surgeon`s and the patient`s entrance to the OR (p=0.033), incision to suture time (p<0.0001), whole operating room time (p<0.0001) and the sum of setup and post processing time (p=0.011) as well as the sum of incision to suture time and time of surgical action (p<0.0001). Furthermore, in this case, specialists arrived later to the OR but took less time for all the other actions.
Moreover, considering tonsillectomy, there were significant differences between residents and specialists in incision to suture time (p<0.0001), whole OR time (p<0.0001) and the sum of incision to suture time and time of surgical action (p<0.0001). All time durations were significantly longer when the surgery was performed by residents.
In addition, the time between entering of the surgeon and patient into the operating room (entrance time) (p=0.009), setup time (p=0.007), incision to suture time (p=0.002), post-processing time (p=0.015), whole operating room time (p=0.004), time of surgical action (p=0.040) and the sum of incision to suture time and time of surgical action (p=0.001) differed significantly for tonsillectomy with uvulopalatopharyngoplasty depending on whether it was performed by residents or specialists. In addition, residents entered the operating room earlier but took longer surgery times than specialists.
Analyzing operating room times of intracapsular tonsillectomies, residents took significantly more time for incision to suture (p<0.0001), whole OR time (p<0.0001), and the sum of incision to suture and surgical action (p<0.0001).
Finally, there was a significant difference in the post processing time after lateral parotidectomies of residents compared to specialists (p=0.002). In this case, post-processing times of specialists were longer.
For some surgical procedures (Midface revision after bone fractures, submandibulectomy and tracheostomy) no statistically significant differences could be found. This may partly be attributed to the rather small sample sizes of the relevant subgroups.
In summary, specialists often take more time until they enter the OR, but then they perform surgeries faster than residents.
Residents and specialists also differ sometimes in their time estimates (table 3). When asked about the average incision to suture time of all surgeons, estimations were significantly different in the case of implantation of hypoglossal nerve stimulator (p=0.034), midface revision after bone fractures (p=0.010), microlaryngoscopy with panendoscopy (p=0.028), tonsillectomy and lateral parotidectomy (p=0.036).
In regard to post-processing time, significant variable durations were presumed for implantation of cochlear implant (p=0.041), midface reconstruction after bone fractures (p=0.020), submandibulectomy (p=0.018), tumor excision with neck dissection (p=0.023) and total parotidectomy (p=0.040).
Estimated durations of preparation time by residents and specialists only differed significantly in terms of implantation of a stimulator of hypoglossus nerve (p=0.021) and total parotidectomy (p=0.040).
There were significant differences between self-estimation of surgery times and objective times for the following procedures: midface revision after bone fractures (p=0.005), septoplasty (p=0.021), tonsillectomy (p=0.022), tracheostomy (p=0.016), tonsillectomy with uvulopalatopharyngoplasty (p=0.012) and intracapsular tonsillectomy (p=0.006).
Specialists always estimated longer durations than residents, except for their own OR time. Concerning their own OR time, specialists expected less time than residents for septoplasty, tonsillectomy, tracheotomy and tonsillectomy with uvulopalatopharyngoplasty.
A comparison of the estimated and effectively measured OR times by specialists revealed biased estimations, especially of preparation time and incision to suture time, and rarely also of post-processing time. Specialists underestimated post-processing time only for panendoscopy including microlaryngoscopy (p=0.015), and for septorhinoplasty (p=0.007). Incision to suture time of most surgeries was overestimated by specialists. The median expected incision to suture time was significantly higher than that measured in case of extirpation of a cervical lymph node (p=0.024), implantation of hypoglossal nerve stimulator (p=0.039), midface reconstruction after bone fractures (p=0.008), panendoscopy including microlaryngoscopy (p=0.001), sialendoscopy (p=0.046) and tonsillectomy (p=0.001). Specialists only underrated real incision to suture time of one-sided neck-dissections (p=0.007). In contrast, they significantly underestimated preparation times for implantation of a cochlear implant (p<0.0001), extirpation of a cervical lymph node (p<0.001), implantation of hypoglossal nerve stimulator (p=0.009), midface reconstruction after bone fractures (p=0.001), mastoidectomy (p=0.045), one-sided neck-dissection (p<0.001), sinus surgery (p<0.001), septoplasty (p=0.009), septorhinoplasty (p<0.0001), sialendoscopy (p=0.036), stapes surgery (p=0.001), submandibulectomy (p=0.040), tracheostomy (p=0.01), tympanoplasty (p<0.0001), lateral parotidectomy (p<0.001) and total parotidectomy (p<0.001).
In summary, specialists poorly estimated post-processing time in two out of 22 types of surgeries, incision to suture time in seven out of 22 types and preparation time in 16 out of 22 types of surgeries.
In the case of significantly false estimations, residents generally underestimated overall time.
Thus, the analysis showed an underestimation of post-processing time by residents for midface reconstruction after bone fractures (p=0.02), panendoscopy including microlaryngoscopy (p<0.001), nasal septoplasty (p=0.002), submandibulectomy (p=0.014), tracheostomy (p=0.001) and tonsillectomy with uvulopalatopharyngoplasty (p=0.001). A comparison between objective incision to suture time and estimated time revealed significant underestimations in case of sinus surgery (p=0.013), tonsillectomy (p=0.04) and tonsillectomy with uvulopalatopharyngoplasty (p<0.001).
Residents assume too short preparation times for extirpation of a cervical lymph node (p<0.0001), midface reconstruction (p<0.0001), sinus surgery (p<0.0001), nasal septoplasty (p<0.0001), submandibulectomy (p<0.0001), tracheostomy (p<0.0001) and lateral parotidectomy (p<0.0001).
In summary, residents underestimated objective preparation and post-processing time in seven out of 15 types of surgeries and incision to suture time in three out of 15 different types.