Question

A study reports different hospital admission rates for various diseases, potentially affecting the observed association. What type of bias does this represent?

• A. Confounding bias
• B. Recall bias
• C. Berksonian bias
• D. Selection bias

Hint:

Berksonian bias = Hospital-based selection bias where admission rates distort exposure–disease association.

Answer 1

The Correct Option is C

To determine the type of bias described in the question, it is essential to understand the context and the definitions of different types of biases.

1. Understanding Berkson's Bias:
   • Berkson's bias, also known as Berksonian bias, occurs when there is differential admission to a hospital related to the disease and exposure status. It is common in hospital-based studies where the sample is not representative of the general population due to the association between the exposure and disease influencing hospital admission rates.
   • This bias affects studies that use hospital records to estimate associations between risk factors and health outcomes, leading to an overestimation or underestimation of the association.
2. Analysis of the Given Situation:
   • The question specifically mentions different hospital admission rates for various diseases, which can directly relate to Berkson's bias, as it highlights the altered association between the disease and hospital admission.
3. Ruling Out Other Options:
   • Confounding Bias: This bias occurs when an external factor is related to both the exposure and outcome, leading to a distorted apparent association. The scenario here reflects admission bias, not confounding bias.
   • Recall Bias: This bias predominantly affects retrospective studies where participants may remember past events differently but is unrelated to hospital admission rates.
   • Selection Bias: While Berkson's bias is a type of selection bias, general selection bias usually refers to non-representative samples not related to hospital settings.
4. Conclusion:
   • The described situation aligns perfectly with Berkson's bias due to the focus on hospital admission rates associated with disease prevalence, which affects the observed association.