Question

A large number of Tuberculosis patients who visited Bihar’s public healthcare system for more than six months participated in the 2011 BEST-TB Survey. The BEST-TB Survey collected information on Tuberculosis symptoms, treatment effects and sociodemographic characteristics of Tuberculosis patients.

A study randomly sampled 200 patients from the BEST-TB Survey database and analysed their questionnaire responses to evaluate the risk of treatment discontinuation.

Which of the following modifications would have made this study an observational study?

• A. Direct observation of patients with Tuberculosis, instead of analysis of past survey data.

• B. Random assignment of Tuberculosis patients to public health care treatment groups.

• C. Inclusion of a control group of Tuberculosis patients who have not received any treatment.

• D. Selection of Tuberculosis patients based on volunteer response sampling.

• E. No modifications are necessary. The study was already an observational study.

Answer 1

E. No modifications are necessary. The study was already an observational study.

• A. Direct observation of patients with Tuberculosis, instead of analysis of past survey data.

This is incorrect since without analysis, the purpose of the study doesn't come into the picture.

• B. Random assignment of Tuberculosis patients to public health care treatment groups.

This is an example of experimental study since the subjects will be given treatments.

• C. Inclusion of a control group of Tuberculosis patients who have not received any treatment.

This would lead to inclusion of other subjects along with subject of interests.

• D. Selection of Tuberculosis patients based on volunteer response sampling.

This would include bias in the selection since they would be selected based on the responses. The analysis would be done before the selecting the subjects.