Use of ureteric stents
Data were extracted for all patients that had been admitted to hospital as an emergency admission during the six year study period with a diagnosis of urinary tract stones using the International Statistical Classification of Diseases and Related Health Problems – 10th revision (ICD-10) codes N201, N202, N209. Patients with kidney stones, bladder stones and stones in other areas of the lower urinary tract were not included in the dataset. Key medical procedures of interest during the admission were use of a ureteric stent (OPCS codes M274, M292), use of ureteroscopy (OPCS codes M271, M272, M273, M281, M282, M283, M288, M289) and use of ESWL (OPCS codes M141, M311). These data were then linked to any subsequent elective ureteroscopy or ESWL procedure conducted in the 30 days following the emergency admission, where a stent had not been fitted during the initial emergency admission.