11
Cross-Sectional Study
Begin with:
Defined Population
Then:
Gather Data on Exposure and Disease
Exposed, with Disease
Exposed, No Disease
Not Exposed, with Disease
Cancer
Ruddy KJ, et al: J Clin Oncol. 2014 Apr 10;32(11):1151-6
Cross-Sectional Studies
Strengths:
Useful for public health surveys Useful for public policy (allocation of resources) Good initial step in evaluating associations Cost-effective use of resources
Not Exposed, No Disease
Prevalence and Control of Diabetes in Chinese Adults
Ning Guang et al: JAMA. 2013 Sep 4;310(9):948-59
Prospective Study of Fertility Concerns and Preservation Strategies in Young Women With Breast
3
Randomized-Clinical Trial Cohort Studies Case Control Studies Cross Sectional Studies Case Report
4
Case Report/Case series
5
Case Report/Case series
Sample: single patient or multiple patients Design: Descriptive-no comparison is given with
Types of Clinical Study Design and clinical application
Lin-Quan Tang Department of Nasopharyngeal carcinoma, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
6
Case-Exsample: Squamous-Cell Carcinoma of the Penis with Human Papillomavirus
7
The New England Journal of medicine
Case-Exsample: Long-Term Disease Control in a Patient With Recurrent Bone-Only Oligometastatic Nasopharyngeal Carcinoma
Case Report/Case
Series
Cross-
Case-
Sectional Control
Cohortຫໍສະໝຸດ Randomized Clinical Trials (RCT)
2
Hierarchy of Evidence
Higher Quality Evidence
Lower Quality Evidence
9
Cross-Sectional Studies
10
Cross-Sectional Studies
Sample: includes a sample of everyone in a population, regardless of exposure or outcome status
Design: In each individual, simultaneously determine the exposure and disease status
“Snap shot”; No follow-up data Examples:
Prevalence surveys (How common is kidney disease in a population?)
Etiology (Is hypertension associated with prevalent kidney disease?)
Learning Objectives
1
Learn the types of study designs used in clinical research
2
Provide an overview of observational and intervention study design
3
Understand the strengths and weakness of study designs
Types of Study designs
Study Designs
Observational Studies: Observe exposures and
outcomes
Clinical (Experimental) Trials: Assign exposure and observe outcomes
an untreated group Unique finding or association reported Example:
- Anecdotal patients: A patient who take vitamins is “cure” of cancer
- Medication side effect
8
J Clin Oncol. 2014 Jun 9
Case Report/Case series
Strengths:
Good initial step in evaluating associations
Limitations:
No control group Causation can not be determined