An investigator wants to assess the association between the socioeconomic class of families (classified into ordered categories I to V) and their level of satisfaction with health services (rated on an ordinal scale). The most appropriate measure of correlation is:

• A Spearman rank correlation coefficient ✓
• B Pearson correlation coefficient
• C Chi-square test
• D Regression coefficient

Explanation

Spearman rank correlation is a non-parametric measure used when one or both variables are ordinal or ranked, as with socioeconomic classes and satisfaction scores. Pearson correlation requires both variables to be measured on an interval or ratio scale with an approximately linear, normally distributed relationship. Chi-square tests association between nominal categories but gives no direction or strength of monotonic relationship, and regression predicts a dependent variable rather than measuring rank agreement.

Reference: Mahajan's Methods in Biostatistics for Medical Students and Research Workers, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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