Pemanfaatan program jaminan persalinan berdasarkan karakteristik pasien di Puskesmas Bukoposo Kecamatan Way Serdang Kabupaten Mesuji Propinsi Lampung tahun 2012 = Utilization of labor assurance program based on patient characteristic at Bukoposo public health center Way Serdang Sub-district, Mesuji Regency, Lampung Province 2012