A guide to selecting the appropriate patient reported outcome (PRO) measure for a study

1. How to Select a Patient Reported Outcome Measure
Dr Keith Meadows, DHP Research & Consultancy Ltd
Copyright DHP Research & Consultancy Ltd 2011 All rights reserved

2. Tip 1: Always have a hypothesis
A PROM should be selected on the basis of a clear rationale as to why it is being used and formulating
a hypothesis will help you to get clear in your mind what it is you want to measure and why.
A hypothesis is a prediction as to what you think will happen and will be linked to the objectives of the
study, patient population, disease and any intervention under evaluation.
The point is that formulating a hypothesis helps you define just what it is you want to measure, from
which you can then identify what would be the most appropriate patient outcome measure to choose.

3. Tip 2: Ensure the content of
the PROM is relevant
PROMs measure a wide range of health concepts In contrast, disease-specific or condition-specific
including, health status, health-related quality measures have been developed to capture those
of life, QoL, well-being, treatment satisfaction, elements of health and QoL of relevance to a
symptoms and functioning. specific patient group.
PROMs can be generally categorised as generic Examination of the measure’s content by looking
and disease or condition-specific, with each at the individual items and response options
having their own strengths and weaknesses. will also give a good idea as to how relevant the
measure is but, most importantly the measure’s
The generic PROM measures health concepts that content should be based on an explicit theoretical
are of relevance to a wide range of patient groups or conceptual framework.
and the general population and as such can be
used for comparison across different conditions as From this you should be able to identify which
well as with healthy populations. items are linked to the particular health concepts
that are purported to be measured.
Due however, to the generic nature of their content,
they will most likely include items that are not
particularly relevant to many patient groups.
Generic measures are also more likely to exclude
content that is of particular relevance
to a specific disease group.

4. Tip 3: Ensure the selected measure is
acceptable to your patient group
In addition to establishing the relevance of the measure’s content, it’s important that the selected
PROM does not pose a significant burden on the participant when completing it, resulting in the
possibility of a lowered response rate.
Length is of course important, the longer the measure the more likely participants will fail to complete
it, however, there is evidence that participants will answer a long questionnaire if the content is
perceived as being relevant to them.
Synonymous with length is the time taken to complete the measure. Measures need to be completed
in the shortest time and expecting participants to take half an hour or more to complete it is
unreasonable and can result in lower item response and return rates.
Design of the PROM can also have a significant impact on acceptability. Instruction need to be simple
and clear as does the language, avoiding the use of technical jargon. Layout should not be cramped.

5. Tip 4: Ensure the measure has been
developed with scientific rigour
When selecting a PROM, it’s essential that there is evidence that its development has been carried
out using appropriate methodologies and meets recognised scientific criteria in terms of reliability
and validity.
The PROM should be reliable in so much that it produce the same results on repeated occasions when
administered to the same participants, assuming there has been no change in the measured concept?
We should also look for the ability of the PROM to discriminate between patients, for example, with
varying levels of health, depression and anxiety etc.
When using a PROM to evaluate for example, a clinical intervention, an important requirement is its
ability to detect change as a result. For example the PROM is able to demonstrate changes in score
for groups of patients whose health is known to have changed as a consequence of some form
of intervention.

6. Tip 5: Make sure you can interpret
your PROM data correctly
The interpretation of PROMS data - in terms of what does a score tell us, poses a number of difficulties.
For example, the concepts that PROMs are purported to assess, can mean different things to different
people at different times and contexts. Also understanding the meaning of what a change or difference
in a score means clinically can be problematic.
You need to consider whether you have the expertise and confidence in undertaking the data analysis and
interpreting just what the score might mean. If not, you might find it more beneficial to collaborate with
someone who does.

7. DHP Research & Consultancy Ltd
113 Lower Camden Chislehurst Kent BR7 5JD
Tel: +44 (0)20 8467 3739
Email: kmeadows@dhpresearch.com
www.dhpresearch.com