Epi Night School Extra: Quantitative and Qualitative Research
One's about data. The other is about telling a story. Together, they're a good way to explain the "what" along with the "why."
Quantitative and qualitative research are like the twin engines that drive the rocket of public health. One thrives on numbers and patterns; the other plunges into the depths of human experience. Together, they create a fuller picture, helping epidemiologists and public health professionals understand the “what” and “why” behind health trends and outcomes.
For instance, take the case of a new health app designed to encourage physical activity. Quantitative research (measuring quantities, numbers) might track how many steps users take before and after using the app, measuring averages and testing statistical significance. Qualitative research (measuring qualities, experiences), on the other hand, asks users how they feel about the app, whether its interface motivates them, or if they find it as enjoyable as a brisk walk with a good podcast.
Quantitative research operates in the realm of numbers: surveys, experiments, and carefully controlled environments. It’s about answering questions like “how many?” or “how often?” If you want to know whether a new vaccine reduces disease by a specific percentage, you’ll turn to the quantitative side of the coin. Think of the landmark polio vaccine trials in the 1950s: massive studies that relied on hard numbers to show the vaccine’s effectiveness.
Qualitative research, however, is more like peeling back the layers of an onion. It’s not about counting, but understanding. Through interviews, focus groups, and observations, qualitative research captures the context and emotions behind the numbers. Imagine a study on vaccine hesitancy. Quantitative data might show how many people avoid vaccines, but qualitative data digs into why by exploring concerns, misinformation, and even cultural factors that numbers alone can’t reveal.
One classic example of these approaches working together is the study of HIV testing behavior. Quantitative research identifies how many people are getting tested and trends over time. Qualitative research explores personal stories: what motivates people to seek testing, what barriers they face, and how stigma impacts their decisions. Together, these approaches guide interventions, like making testing more accessible and stigma-free.
But let’s not pretend either approach is perfect. Quantitative research sometimes misses the nuances. It might tell you the “what” without the “why.” Meanwhile, qualitative research, while rich in detail, can be subjective and harder to generalize. That’s why many studies use mixed methods, combining both types of research for a more complete view. It’s like using both a telescope and a microscope to explore the same phenomenon.
In the world of public health, we see these methods intersect beautifully. During the COVID-19 pandemic, quantitative research tracked case counts, vaccine effectiveness, and hospitalizations. Qualitative studies examined how people felt about masks, lockdowns, and vaccines. Thus providing insights that shaped public health messaging.
Quantitative and qualitative research aren’t rivals; they’re teammates. Together, they answer the tough questions, paint the big picture, and uncover the human stories behind the data. Whether it’s exploring the effectiveness of a treatment or understanding the hesitations people have about it, these two approaches remind us that public health is both science and art. And when they work together, they make the world a healthier, better-understood place.
As you continue your journey in the Public Health Night School, ask yourself if the study I share with you is qualitative, quantitative, or mixed methods. And what would you change to improve the studies?
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