Hilary Y. M. Pang, Kelsey Chalmers, Bruce Landon, Adam G. Elshaug, John Matelski, Vicki Ling, Monika K. Krzyzanowska, Girish Kulkarni, Bradley A. Erickson, Peter Cram

Few studies have compared surgical utilization between countries or how rates may differ according to patients' socioeconomic status. To compare population-level utilization of 3 common nonemergent surgical procedures in New York State (US), Ontario (Canada), and New South Wales (Australia) and how utilization differs for residents of lower- and higher-income neighborhoods. This cohort study included all adults aged 18 years and older who were hospitalized for pancreatectomy, radical prostatectomy, or nephrectomy between 2011 and 2016 in New York, between 2011 and 2018 in Ontario, and between 2013 and 2018 in New South Wales. Each patient's address of residence was linked to 2016 census data to ascertain neighborhood income. Data were analyzed from August 2019 to November 2020. Primary outcomes were (1) each jurisdiction's per capita age- and sex-standardized utilization rates (procedures per 100 000 residents per year) for each surgery and (2) utilization rates among residents of lower- and higher-income neighborhoods. This study included 115 428 surgical patients (25 780 [22.3%] women); 5717, 21 752, and 24 617 patients in New York were hospitalized for pancreatectomy, radical prostatectomy, and nephrectomy, respectively; 4929, 19 125, and 16 916 patients in Ontario, respectively; and 2069, 13 499, and 6804 patients in New South Wales, respectively. Patients in New South Wales were older for all procedures (eg, radical prostatectomy, mean [SD] age in New South Wales, 64.8 [7.3] years; in New York, 62.7 [8.4] years; in Ontario, 62.8 [6.7] years; P < .001); patients in New York were more likely than those in other locations to be women for pancreatectomy (New York: 2926 [51.2%]; Ontario: 2372 [48.1%]; New South Wales, 1003 [48.5%]; P = .004) and nephrectomy (New York: 10 645 [43.2%]; Ontario: 6529 [38.6%]; 2605 [38.3%]; P < .001). With the exception of nephrectomy in Ontario, there was a higher annual utilization rate for all procedures in all jurisdictions among patients residing in affluent neighborhoods (quintile 5) compared with poorer neighborhoods (quintile 1). This difference was largest in New South Wales for pancreatectomy (4.65 additional procedures per 100 000 residents [SE, 0.28]; P < .001) and radical prostatectomy (73.46 additional procedures per 100 000 residents [SE, 1.20]; P < .001); largest in New York for nephrectomy (8.43 additional procedures per 100 000 residents [SE, 0.85]; P < .001) and smallest in New York for radical prostatectomy (19.70 additional procedures per 100 000 residents [SE, 2.63]; P < .001); and smallest in Ontario for pancreatectomy (1.15 additional procedures per 100 000 residents [SE, 0.28]; P < .001) and nephrectomy (-1.10 additional procedures per 100 000 residents [SE, 0.52]; P < .001). New York had the highest utilization of nephrectomy (28.93 procedures per 100 000 residents per year [SE, 0.18]) and New South Wales for had the highest utilization of pancreatectomy and radical prostatectomy (6.94 procedures per 100 000 residents per year [SE, 0.15] and 94.37 procedures per 100 000 residents per year [SE, 0.81], respectively; all P < .001). Utilization was lowest in Ontario for all procedures (pancreatectomy, 6.18 procedures per 100 000 residents per year [SE, 0.09]; radical prostatectomy, 49.24 procedures per 100 000 residents per year [SE, 0.36]; nephrectomy, 21.40 procedures per 100 000 residents per year [SE, 0.16]; all P < .001). In this study, New York and New South Wales had higher per capita surgical utilization and larger neighborhood income-utilization gradients than Ontario. These findings suggest that income-based disparities are larger in the United States and Australia and smaller in Canada and highlight trade-offs inherent in the health care systems of different countries.