The effect of complementary private health insurance on the use of health care services.

This study estimates the effect of complementary private health insurance (PHI) on the use of health care. The empirical analysis focuses on an institutional setting in which empirical findings are still limited; namely on PHI covering co-payment for treatments that are only partly financed by a universal health care system. The analysis is based on Danish data recently collected specifically for this purpose, which makes identification strategies assuming selection on observables only, and on both observables and unobservables also, both plausible and possible. We find evidence of a substantial positive and significant effect of complementary PHI on the use of prescription medicine and chiropractic care, a smaller but significant effect on dental care, weaker indications of effects for physiotherapy and general practice, and finally that the use of hospital-based outpatient care is largely unaffected. This implies that complementary PHI is generally not simply a marker of a higher propensity to use health care but induces additional use of some health care services over and above what would be used in the absence of such coverage.