Why are ambulatory surgical patients admitted to hospital?: Prospective study

Abstract

Background: Once Ambulatory Surgery (AS) has been demonstrated to be an effective alternative to hospitalisation for many surgical patients, it is necessary to establish clinical indicators to evaluate objectively the quality of care that is being given. Hypothesis: The unplanned admission index (UAI) is a valid and easy indicator of the management and quality of care in ambulatory surgery units. Design: Prospective study. Setting: Public regional hospital level I (less than 200 beds). Main outcome measure: Unplanned admission index (UAI). Patients and methods: Between September 1997 and October 2000, 3502 patients were operated on in our ambulatory surgery unit. The analysed surgical services were General surgery (844 patients), Orthopaedics (646 patients), Urology (499 patients), ENT (329 patients), Ophthalmology (1007 patients) and Gynaecology (177 patients). A prospective study of all the patients was made, with analysis of the following parameters: (1) global and accumulated UAI (per months and years); (2) UAI by surgical specialities; (3) UAI by causes; (4) UAI by type of operation; (5) UAI by type of anaesthesia; (6) case-mix, according to average weight of diagnostic related groups classification (DGR). Results: The global UAI was 4.1%. By specialities, the UAI was 10.7% in Gynaecology; 6.1% in ENT; 5.9% in General surgery; 3.4% in Orthopaedics; 2.3% in Ophthalmology and 2% in Urology. The most frequent causes of unplanned admission were haemorrhage: 15.9%; more extensive surgery than anticipated: 15.3%; postoperative pain: 12.5%; nausea and vomiting: 10.4%; and drowsiness and dizziness: 6.9%. The types of operation with the highest UAI were, gynaecological laparoscopy: 50%; hysteroscopy: 26%; haemorrhoidectomy: 25%; septoplasty: 22%; strabismus surgery: 11%; orchiopexy: 11%; hydrocelectomy: 10%; inguinal hernia repair: 8%. Conclusions: (1) Classification of UAI by specific causes of admission and incorrect selection of patients may detect on-line problems and allow the application of concrete solutions to reduce the UAI index. (2) In order to compare the results amongst different ambulatory surgery units, an international classification of ambulatory patients must be applied. In the same way, an objective index to evaluate the surgical complexity and the patients' morbidity should be developed. (3) The assessment of processes and results should be based on the selection of standard indicators with systematic and periodic measurement.