Common Mistake in Adjusting Sample Size for Anticipated Dropouts in Clinical Trials
W H I T E P A P E R
Common Mistake in Adjusting Sample Size for Anticipated Dropouts in Clinical Trials Mr. Prasanth S, Ms. Rajani V and Dr. A.K. Mathai
www.makrocare.com
WHITE
PAPER
Common Mistake in Adjusting Sample Size for Anticipated Dropouts in Clinical Trials
D
ay by day the clinical trial field is expanding like anything. New molecules are needs to be experimented in human beings and the existing drugs are needs to be monitored for long term safety. Thus Phase I to IV clinical trial activities are increasing exponentially all over the world. However, it is difficult to work with large populations and hence researchers work with representative samples of the patient population. Estimation of sample size is critical in planning clinical trial because this is usually the most important factor determining the time and cost of the study. In most of the studies, the sample size calculations are based on the primary research question/objective that the investigator wants to do research. The sample size calculation must be taken into account of all available data, cost of the study, support facilities, and ethics of subjecting patients to research. Basic elements considered for estimating sample size include level of significance, power of the study, clinically meaningful difference, and the variability or standard deviation and of course the availability of patients.
The initial sample size estimated in the study need to be increased in accordance with the expected response rate, loss to follow up, lack of compliance, and any other predicted reasons for loss of subjects.
Previous studies in the same population will give an estimate of the expected number of subjects dropped out at the end of the study. Adverse events due to study treatment, follow up length, lack of efficacy etc.
will
Common Mistake in Adjusting Sample Size for Anticipated Dropouts in Clinical Trials Mr. Prasanth S, Ms. Rajani V and Dr. A.K. Mathai
www.makrocare.com
WHITE
PAPER
Common Mistake in Adjusting Sample Size for Anticipated Dropouts in Clinical Trials
D
ay by day the clinical trial field is expanding like anything. New molecules are needs to be experimented in human beings and the existing drugs are needs to be monitored for long term safety. Thus Phase I to IV clinical trial activities are increasing exponentially all over the world. However, it is difficult to work with large populations and hence researchers work with representative samples of the patient population. Estimation of sample size is critical in planning clinical trial because this is usually the most important factor determining the time and cost of the study. In most of the studies, the sample size calculations are based on the primary research question/objective that the investigator wants to do research. The sample size calculation must be taken into account of all available data, cost of the study, support facilities, and ethics of subjecting patients to research. Basic elements considered for estimating sample size include level of significance, power of the study, clinically meaningful difference, and the variability or standard deviation and of course the availability of patients.
The initial sample size estimated in the study need to be increased in accordance with the expected response rate, loss to follow up, lack of compliance, and any other predicted reasons for loss of subjects.
Previous studies in the same population will give an estimate of the expected number of subjects dropped out at the end of the study. Adverse events due to study treatment, follow up length, lack of efficacy etc.
will