Methodology

Each patient reported outcome measurement scale (PROMS) is subject to a standardized procedure before inclusion in the SeleQt platform.

This procedure includes:

• Assessment of the eligibility criteria by an expert committee
• Expertise by an epidemiologist of the general characteristics of the instrument and its validation using the COSMIN group’s criteria
• Development of an entry form
• Development of a scoring manual and SAS® macro by a biostatistician

Inclusion of a PROMS into our database

Any questionnaire proposed to be included in our database must meet the following criteria:

• The PROMS aims to measure a latent variable
• The PROMS has to be a complex measurement scale, ie involving at least several items on one dimension
• The PROMS should at least have a French version
• A validation article of the French version must be available in a peer-reviewed journal

If it meets these criteria, the PROMS characteristics are assessed by a member of our team, if necessary the contentious issues are decided collegially within an expert committee.

Based on the available information (questionnaire, paper, instructions,…) a summary sheet describes the general characteristics (target population, target domains, size of the questionnaire...).

Evaluation of the validation using the COSMIN checklist

Any PROMS included in the SeleQt platform is considered to have been validated by its authors in the inclusion paper. To assess the quality of the validation process under current expectations, we used the COSMIN check-list (www.cosmin.nl). This check-list explores 9 areas (internal consistency, reliability, measurement error, content validity, structural validity, hypothesis testing, cross-cultural validity, criterion validity, and responsiveness).

The items of the COSMIN check-list are quoted with a Likert scale ("excellent, good, fair, poor"), but all response categories are not available for each item (eg, "Was the percentage of missing items given? " admits only two answers "excellent " if  the answer is yes and "good "if not).

Each validation of the PROMS French version has been evaluated using the relevant items according to the instructions of the COSMIN group. The results are available in three forms on the SeleQt platform:

• Raw: the answer for each item ("excellent, good, fair or poor") is provided. This can only be interpreted with the help of the COSMIN check-list and its manual since all items do not have the same levels of answer.
• Summarized: that is the form recommended by the COSMIN group, where only the total score for each domain explored by the COSMIN check-list is shown. This score is also in the form: "excellent, good, fair or poor", and corresponds to the rating of the worst item of the corresponding domain of the COSMIN check-list.
• Intermediate: offering a good level of compromise between the summarized form that provides little information and the raw form. We recoded each item  in “Yes / No / Unknown / Not applicable”. The recoding algorithm depends on the items and was determined collegially by the experts of SeleQt platform to allow for each item a quick evaluation of the validation process quality.

Note: The psychometric properties of the instruments are not assessed by the experts of the SeleQt platform. Their assessment is left to the users.

Development of an entry form

An entry form is developed under Microsoft Access® by data entry technicians of the CIC-EC. This form is then exported automatically as an Epidata entry form. EpiData software is usefull for creating electronic versions of questionnaires (entry forms) to ease data entry and create good quality raw data files for further analysis. It is a free software which can be downloaded via: http://www.epidata.dk/download.php.

Development of a scoring manual and SAS® macro

From the documents available, a biostatistician develops a short scoring manual and a SAS® macro for the questionnaire. If necessary the author of the questionnaire is contacted. The short scoring manual is validated by an epidemiologist and the macro by another biostatistician, independently.