Which patients receive surgery in for-profit and non-profit hospitals in a universal health system? An explorative register-based study in Norway.

Objectives: To compare the socioeconomic status (SES) and case-mix among day surgical patients treated at private for-profit hospitals (PFPs) and non-profit hospitals (NPs) in Norway, and to explore whether the use of PFPs in a universal health system has compromised the principle of equal access regardless of SES.

Design: A retrospective, exploratory study comparing hospital types using the Norwegian Patient Register linked with socioeconomic data from Statistics Norway by using Norwegian citizens' personal identification numbers.

Setting: The Norwegian healthcare system.

Population: All publicly financed patients in five Norwegian metropolitan areas having day surgery for meniscus (34 100 patients), carpal tunnel syndrome (15 010), benign breast hypertrophy (6297) or hallux valgus (2135) from 2009 to 2014.

Primary Outcome Measure: Having surgery at a PFP or NP.

Results: Across four unique procedures, the adjusted odds ratios (aORs) for using PFPs were generally lower for the lowest educational level (0.77-0.87) and the lowest income level (0.68-0.89), though aORs were not always significant. Likewise, comorbidity and previous hospitalisation had lower aORs (0.62-0.95; 0.44-0.97, respectively) for having surgery at PFPs across procedures, though again aORs were not always significant. No clear patterns emerged with respect to age, gender or higher levels of income and education.

Conclusions: The evidence from our study of four procedures suggests that equal access to PFPs compared with NPs for those patients at the lowest education and income levels may be compromised, though further investigations are needed to generalise these findings across more procedures and probe causal mechanisms and appropriate policy remedies. The finding that comorbidity and previous hospitalisation had lower odds of treatment at PFPs indicates that NPs play an essential role for more complex patients, but raises questions about patient preference and cream skimming.