<prompt> When a diagnostic test is used in series mode then-Sensitivity increases but the specificity decreasesSpecificity increases bu the sensitivity decreasesBoth sensitivity and specificity increasesBoth sensitivity and specificity decreases  <response>: Ref:Parks 23rd edition pg 137 When used in series: Sensitivity decreases Specificity increases PPV increases NPV decreases When used in parallel : Sensitivity increases Specificity decreases PPV decreases NPV increases 