PROBLEMS PROBLEMS OF OF

BORDERLINEBORDERLINE

By Sneha Raj . PRoll No 94Guided By:

Sipra Madam

Which of the following is more important in screening..??

Sensitivity or specificity No categorical answer can

be given

Shaded area → persons with disease + Persons without disease

• E is frequently used as cutoff point

• E minimizes false positives and false negatives

Many physiological variables show this type of distribution

No sharp dividing line Borderline group contains

homogenous sample of persons

Blood Pressure & Blood Sugar

• Cutoff point increases - sensitivity decreases • Cutoff point decreases - sensitivity increases• In screening for disease a prior decision is made about the cutoff point

Factors Considered In Fixing A Cutoff Point• Disease prevalence • Disease

Disease prevalence: If disease prevalence is increased- screening is set at low level- sensitivity is increasedDisease: Lethal disease Prevalent diseases

OTHER PROBLEMS:1.People who participate in screening program may not be those who have most to gain from it2.More expensive & time consuming test..

3.Screening should not be done in isolation.It should be integrated into existing health services.

4. Risks as well as expected benefits must be explained to people to be screened.

14

Screenes

Well

Asymptomatic Sick

Sick

15