Receiver　operating　characteristic　(ROC)　curve　is　a　popular　tool　to　describe　and　compare　the　diagnostic　accuracy　of　biomarkers　when　a　binary-scale　gold　standard　is　available.　However,　there　are　many　examples　of　diagnostic　tests　whose　gold　standards　are　continuous.　Hence,　Several　extensions　of　receiver　operating　characteristic　(ROC)　curve　are　proposed　to　evaluate　the　diagnostic　potential　of　biomarkers　when　the　gold　standard　is　continuous-scale.　Moreover,　in　evaluating　these　biomarkers,　it　is　often　necessary　to　consider　the　effects　of　covariates　on　the　diagnostic　accuracy　of　the　biomarker　of　interest.　Covariates　may　include　subject　characteristics,　expertise　of　the　test　operator,　test　procedures　or　aspects　of　specimen　handling.　Applying　the　covariate　adjustment　to　the　case　that　the　gold　standard　is　continuous　is　challenging　and　has　not　been　addressed　in　the　literature.　To　fill　the　gap,　we　propose　two　general　testing　frameworks　to　account　for　the　covariates　effect　on　diagnostic　accuracy.　Simulation　studies　are　conducted　to　compare　the　proposed　tests.　Data　from　a　study　that　assessed　three　types　of　imaging　modalities　with　the　purpose　of　detecting　neoplastic　colon　polyps　and　cancers　are　used　to　illustrate　the　proposed　methods.