A community survey reports the prevalence of anaemia in adolescent girls as 56%. The researcher wants to estimate the prevalence with a 5% allowable error and 95% confidence. Which factor does NOT affect the required sample size in this calculation?

• A Estimated prevalence (p)
• B Allowable error (d)
• C Confidence level (Z)
• D Population size (N) when N is large (>10,000) ✓

Explanation

For prevalence studies, the formula n = Z²pq/d² does not require the population size when the population is large (typically >10,000), because the finite population correction factor approaches 1.0. The estimated prevalence (p), allowable error (d), and the Z value corresponding to desired confidence level all directly influence the calculated sample size.

Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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