A community health RN studies melanoma development after frequent tanning salon visits. Studies of this type are classified as which design?

• A. Retrospective
• B. Concurrent
• C. Cross-sectional
• D. Prospective

Answer: (A)

Study designs are distinguished by whether the investigator looks back at exposures after an outcome has occurred or follows people forward in time from exposure to outcome. A retrospective design means the researcher examines past exposure data (often from records or recall) after the disease outcome has occurred, and compares exposure histories between those with the disease and those without. In this scenario, melanoma development is being analyzed after frequent tanning visits, which implies looking back to see if tanning exposure preceded the cancer. That makes it a retrospective study. A cross-sectional approach would assess exposure and disease at one moment in time and can't establish which came first, while a prospective design would start with exposure and follow participants forward to see who develops melanoma.