What impact do prescription drug charges have on efficiency and equity? Evidence from high-income countries

Table 8 The impact of prescription drug charges on the probability of obtaining a prescription drug

Variable	Probability of use	Studies
Co-payment	-	Esposito¹ [45] (US, OS, CD, R); Gardner et al. [137] (NZ, OS, CD, NR); Hillman et al. [138] (US, OS, CD, R); Stuart and Zacker [123] (US, OS, CD, R); Watt et al. [139] (NZ, OS, CD, NR)
Co-insurance	-	Lohr et al. [140] (US, ES, CD, NR)
Deductible	-	Blais et al. [141] (CA, NS, TD, R)
Mixed system	-	Goldman et al. [142] (US, OS, CD, R); Ozminkowski et al. [143] (US, OS, CD, R); Smart and Stabile [100] (CA, NS, CD, R)
Change from:
deductible and co-insurance to income-based deductible	-	Kozyrskyj et al. [53] (CA, NS, CD, R)
Insurance coverage
Primary (vs. none)	+	Smith and Garner [111] (US, NS, CD, NR); Thomas et al. [144] (US, OS, CD, R)
Supplementary (vs. none)	+	Adams et al. [145] (US, OS, CD, R); Blustein [127] (US, OS, CD, R); Caussat and Glaude [34] (FR, OS, CD, R); Coulson and Stuart [146] (US, OS, CD, R); Genier et al. [147] (FR, OS, CD, R); Grignon and Perronin [121] (FR, NS, CD, R); Raynaud [148] (FR, OS, CD, R); Raynaud [134] (FR, OS, CD, R); Rogowski et al. [149] (US, OS, CD, R); Stuart and Grana [33] (US, OS, CD, R)
Supplementary (vs. none)	0	Christiansen et al. [52] (DK, OS, CD, R)
Supplementary public (vs. private)	+	Raynaud [148] (FR, OS, CD, R); Raynaud [134] (FR, OS, CD, R)

¹This study examined the probability of using a specific statin compared to the probability of using other statins when there were differing co-payments for each statin.
Country: CA = Canada; DK = Denmark; FR = France; NZ = New Zealand; US = United States
Type of study: ES = experimental study; NS = natural study; OS = observational study
Type of data analyzed: CD = cross-sectional data; TD = time-series data; PD = panel data
Type of statistical analysis used: R = regression techniques; NR = no regression techniques