Cherkin DC, Grothaus L, Wagner EH. Is magnitude of co-payment effect related to income? Using census data for health services research. Soc Sci Med. 1992 Jan;34(1):33-41.
Cherkin DC, Grothaus L, Wagner EH. Is magnitude of co-payment effect related to income? Using census data for health services research. Soc Sci Med. 1992 Jan;34(1):33-41.