Table 1 Comparison between what is known about use of PRO instruments for routine clinical practice and new issues highlighted in this commentary

PROs instruments have generally been developed for research purposes. They tend to be long in order to maximize the amount of data available for researchers to analyze.

Long research questionnaires are not practical as part of routine care. Patients who have not specifically volunteered to complete questionnaires may have poor compliance with time-consuming instruments. No more than 15–20 items are recommended in a questionnaire,with no more than 5 – 7 items in a domain.

Patient who do not have good language skills are not typically invited on research studies.

Patients with low language skills present in clinics. Questionnaires need to include simplified language.

Instruments are traditionally developed by gathering a group of patients, asking about their symptoms and designing items based on wide cross-section of symptoms.

Many questionnaire items can be inappropriate for specific subgroups of patients. Different instruments sometimes need to be used for different groups of patients, depending on their expected symptoms.

Survey instruments are validated by providing group level statistics.

Group level statistics can obscure problems when applying an instrument to certain subgroups. It is important to critically look at each item and think through what might lead to misleading responses.

Research design and statistical methods for psychometric studies has focused on instruments for research use.

New designs and methods are needed to develop instruments for clinical use.