What a qualitative study can tell you
It does not measure whether a treatment works. It finds out what something is like, in enough detail that you recognise it. That is a different question, with answers a trial cannot produce.
Written and reviewed by Reza D, OTR/L, MOT, CPACC · Published 10 September 2026 · Free to read
A qualitative study does not measure whether a treatment works. It finds out what something is like, in enough detail that you recognise it. That is a different question, and it has answers a trial cannot produce.
What question does a qualitative study answer?
It answers what, how and why, for a specific group of people in a specific situation. What did they find difficult. How did they explain it to themselves. Why did they stop coming. A trial can tell you that half the participants dropped out. Only a qualitative study can tell you what they said when asked.
The output is themes rather than numbers. A theme is a pattern the researchers found across their interviews, stated in a way you can check against the quotes they publish. That is the evidence: not a p value, but whether the interpretation is supported by what people actually said.
| Approach | What it produces | When it is the right choice |
|---|---|---|
| Grounded theory | A theory built up from the data, describing a process people go through. | When you want to understand how something unfolds over time and no adequate explanation exists yet. |
| Phenomenology | A description of what an experience is actually like from the inside. | When the point is the lived experience itself, not the process or the service around it. |
| Thematic analysis | Patterns across a set of interviews, organised into named themes. | The general-purpose choice. Most of the qualitative papers here use it. |
| Photovoice and participatory methods | Accounts produced with participants rather than about them, often using their own images. | When the group is usually spoken for, and the point is to hear them directly. |
Why does every qualitative paper here rate very low?
Because the certainty rating on this site answers one question: how much weight can this single paper carry as evidence that a treatment works. A qualitative study is not built to answer that, so it rates at the bottom of a scale it was never on.
That is a limitation of the rating, not a criticism of the research. The certainty guide explains where the rating comes from and why nothing here is ever rated high. Read very low on a qualitative paper as a reminder of what the paper is not claiming, rather than as a mark against it.
What can you actually take from one?
Three things, reliably.
- Language. The words patients use for their own problem are the words that work in the clinic. Qualitative papers publish them verbatim.
- Barriers you would not have guessed. Usually the reason an intervention fails is not the intervention.
- What to ask. A theme is a question you can put to your own patient to see whether it applies to them.
How do you tell a good qualitative study from a weak one?
Five questions, and none of them require statistics.
- Do they show you the data? Themes should come with quotes. If you cannot see what people said, you cannot check the interpretation.
- Do they say who is missing? Fourteen caregivers from one community is a finding about that community. A good paper says so.
- Do they say when they stopped? Recruiting until no new themes appear is a defensible stopping rule. Recruiting until the funding ran out is not, but it happens, and honest papers admit it.
- Is the researcher in the paper? A clinician interviewing their own patients gets different answers than a stranger would. Good qualitative work states the relationship rather than pretending to neutrality.
- Do the conclusions stay inside the data? This is the common failure. A themes paper that ends by recommending the intervention has stepped outside what it can support.
What can it not tell you?
Whether the treatment works, how often, or for whom in general. Participants who describe a programme as helpful are describing their experience, not demonstrating an effect. They were not randomised, there was no comparison, and the people who found it useless are frequently the people who left before anyone interviewed them.
The other thing it cannot do is transfer. A study of nine Japanese therapists setting goals over video is about those nine, in that system. Whether it applies to you is your judgement, and the paper should give you enough detail to make it. If it does not describe the setting clearly enough for you to decide, that is a flaw.
If you are working out how much weight any single paper can carry, the guide on studies that cannot prove anything covers the other designs that answer a real question without answering that one. You can also browse every paper here for occupational therapy.
Written and reviewed by Reza D, OTR/L, MOT, CPACC. Guides are the only pages on Applied Evidence written by a person. Paper summaries are generated by software and marked as such. Last reviewed 10 September 2026.