Community Medicine & Preventive Health Flashcards

Which of the following statistics is the BEST indicator of the overall quality of healthcare in a country?

Answer: Infant mortality rate

Infant mortality rate is the most sensitive indicator of healthcare quality as it reflects nutrition, sanitation, maternal care, and the overall effectiveness of the health system.

A screening test has a sensitivity of 85% and specificity of 90%. If the prevalence of the disease increases in the tested population, what happens to the positive predictive value (PPV)?

Answer: PPV increases

As disease prevalence increases, the proportion of true positives among all positive tests rises, so PPV increases accordingly.

According to the Saudi National Immunization Program, which two vaccines are administered at birth?

Answer: BCG and Hepatitis B

The Saudi immunization schedule administers BCG (to prevent tuberculosis) and Hepatitis B vaccine at birth.

A 35-year-old asymptomatic woman undergoes a Pap smear test for cervical cancer detection. This is an example of which level of prevention?

Answer: Secondary prevention

Secondary prevention involves early detection of disease in asymptomatic individuals through screening, such as Pap smears for cervical cancer.

In a case-control study investigating the association between a risk factor and a disease, which measure of association is typically calculated?

Answer: Odds ratio

Odds ratio is used in case-control studies because incidence data is not directly available; it approximates relative risk when disease prevalence is low.

In a clinical trial, neither the participants nor the investigators know who received the active treatment or the placebo. This study design is called:

Answer: Double-blind trial

In a double-blind trial, both participants and investigators are unaware of treatment allocation, reducing performance and detection bias.

Which of the following is the MOST important Wilson and Jungner criterion for a disease to be suitable for a screening program?

Answer: An effective treatment must be available and early treatment must improve outcomes compared to late treatment

Screening is only justified if early detection leads to better patient outcomes; if treating early confers no advantage over treating at symptom onset, screening provides no benefit.