RT Book, Section
A1 Greenberg, Raymond S.
A1 Daniels, Stephen R.
A1 Flanders, W. Dana
A1 Eley, John William
A1 Boring, John R.
SR Print(0)
ID 545607
T1 Chapter 6. Diagnostic Testing
T2 Medical Epidemiology, 4e
YR 2005
FD 2005
PB The McGraw-Hill Companies
PP New York, NY
SN 9780071416375
LK accessmedicine.mhmedical.com/content.aspx?aid=545607
RD 2024/04/18
AB The  sensitivity  of  a  diagnostic  test  is  the  likelihood  that  persons  with  the  disease  of  interest  will  have  positive  test  results.  The  specificity  of  a  diagnostic  test  is  the  likelihood  that  persons  who  do  not  have  the  disease  of  interest  will  have  negative  test  results.  Positive  predictive  value  measures  the  likelihood  of  having  the  disease  of  interest  among  those  whose  diagnostic  test  results  are  positive.  Negative  predictive  value  is  the  likelihood  of  not  having  the  disease  of  interest  among  those  whose  diagnostic  test  results  are  negative.  Likelihood  ratios  can  be  used  to  measure  the  extent  to  which  the  likelihood  of  the  disease  of  interest  is  changed  by  the  results  of  a  diagnostic  test.  The  area  under  a  receiver  operating  characteristic  (ROC)  curve  can  be  used  to  assess  the  performance  of  a  diagnostic  test.  Screening  for  a  particular  disease  is  conducted  in  order  to  detect  the  disease  at  an  earlier  stage  than  would  occur  through  routine  methods.  An  error  in  the  evaluation  of  a  screening  test,  known  as  lead  time  bias,  can  occur  when  persons  with  disease  detected  by  screening  appear  to  live  longer  simply  because  of  the  earlier  recognition  of  their  illnesses.  An  error  in  the  evaluation  of  a  screening  test,  known  as  length-biased  sampling,  can  occur  when  persons  with  disease  detected  by  screening  appear  to  live  longer  simply  because  they  have  more  slowly  progressing  illnesses.