Post 3: Cross-sectional Study Design

Cross sectional studies involve the simultaneous collection of exposure and outcome data from a selected group of individuals belonging to a specified population group at a given point in time¹. Collected data can be grouped into diseased/non-diseased and exposed/non-exposed groups and associations can be studied, however as temporality is not taken into account, causality cannot be determined.  Possible limitations include bias from both outcomes that have an effect on the exposure variable and population group selection.  

Image 2: Schematic diagram of Cross-sectional study design

Particularly useful in assessing the burden of disease of health needs of a population, it is a preferred design to find out the prevalence and associated risk factors of a particular outcome or  disease2 .  Application of cross sectional studies are valuable in planning health care, for example, a physiotherapist planning an aged strength training programme, might wish to know the prevalence of different risk factors of osteoporosis in the group under their care so that interventions could be tailored accordingly.

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1    Dickinson K. Ecological Study [unpublished lecture notes]. Flinders University; lecture notes  provided at lecture given 2015 February 20.

2    British Medical Journal [internet]. Case control and cross-sectional study [cited 2015 May 4]. Available from http://www.bmj.com/about-bmj/resources-readers/publications/ epidemiology-uninitiated/8-case-control-and-cross-sectional