Unlike quantitative studies, qualitative studies proceed without formulating hypotheses, and they do not draw conclusions based on numerical data. The information they obtain can be used to generate ideas and hypotheses, which can then be tested with quantitative methods.
Qualitative methods—eg, focus groups, observation, in-depth individual interviews—emphasize the meaning and process of a clinical issue rather than the outcomes of interventions. Consider this simple, fictional example:
An educational intervention designed to improve compliance with asthma care was implemented among patients from indigent families. The intervention improved the rate of maintenance steroid inhaler use by a nonsignificant 3% of participants. Disappointed by this result, the researchers used qualitative methods to try to find out why the intervention did not have a more significant effect.
They met with several small groups of participants for loosely structured interviews known as “focus groups” and asked them specific questions about the educational program. One common theme from the focus group responses was that participants believed the facilitators of the educational intervention were condescending and did not understand the challenges faced by poor families. This finding led the researchers to redesign their intervention with facilitators who were better trained to support the needs of their targeted patient population.
When qualitative studies are helpful
In general, research topics that relate to subjects’ perceptions, attitudes, or opinions are well suited to qualitative research methods. Unlike clinical trials, no attempt is made in qualitative studies to compare identical groups or minimize confounding. In fact, differences among participants contribute positively to understanding of a topic.
However, like quantitative researchers, qualitative researchers begin with a clinical question. Qualitative methods, however, permit changing the question as new information is gathered. Rather than using a predetermined time frame or number of study subjects, qualitative studies continue until sufficient data have been gathered. Researchers may end the study when the responses of participants start falling into certain themes or patterns and additional responses do not add any new information.
CORRESPONDENCE
Sukanya Srinivasan, MD, MPH. E-mail: srinivasans@upmc.edu