Table 3.

Summary of the quality evaluation of the 23 included studies of this systematic review

Reference	Main strengths	Main limitations	Quality according to the quality assessment protocol
Aladul et al 201918	Results logically and clearly displayed	Details of the questionnaire form were not available, discussion on methodology partly lacking	High
Baji et al 2016a20	Well-described and logically presented methodology, results and discussion	Ethical discussion lacking	High
Baji et al 2016b21	Well-described and logically presented methodology, results and discussion	Critical and ethical discussion partly lacking	High
Chapman et al 201823	Mainly well-described and logically presented methodology, results and discussion	More in-depth information could have been collected by a qualitative study	High
Grabowski et al 201534	Well-described and logically presented methodology, results and discussion	More in-depth information could have been collected by a qualitative study	High*
Hemmington et al 201736	Well-described and logically presented methodology, results and discussion	Details of the questionnaire form were not available, more in-depth information could have been collected by a qualitative study	High
O’Callaghan et al 201710	Well-described and logically presented methodology, results and discussion	More in-depth information could have been collected by a qualitative study	High
van Overbeeke et al 201727	Well-described and logically presented methodology, results and discussion	More in-depth information could have been collected by a qualitative study	High
Aladul et al 201819	Semi-structured interviews provide a more in-depth view on the perceptions of healthcare professional in comparison with short surveys	Exact numbers of respondents which certain opinion (n) not always reported, low number of representatives per each professional group	Moderate*
Barsell et al 201731	Well-presented results and discussion	Details of the questionnaire form were not available, description of methodology lacking, eg, dropout not described, ethical discussion lacking	Moderate
Beck et al 201622	Well-presented results and discussion	Details of the questionnaire form were not available, validity of the instrument unclear, as more in-depth information could have been collected by a qualitative study, dropout not described accurately	Moderate*
Hallersten et al 201630	Results clearly presented	Details of the panel of physicians in different European countries where the respondents were reqruited were not shown. Critical discussion on the method partly lacking	Moderate
Sullivan et al 201728	Results clearly presented	Dropout not described accurately, some inconsistencies in the presentation of methodology and discussion	Moderate*
Waller et al 201729	Well-presented results and discussion	Some inconsistencies in the presentation of methodology, eg, sample selection and dropout	Moderate*
Akhmetov et al 201517	Explicit aims	Clear presentation of results lacking, critical and ethical discussion lacking	Low
Cohen et al 201732	Mainly well-presented results and discussion	Details of the questionnaire form were not available, description of methodology lacking, ethical discussion lacking	Low
Danese et al 201624	Results clearly presented	Details of the questionnaire form were not available, critical and ethical discussion partly lacking, description of methodology partly lacking	Low
Danese et al 201425	Results clearly presented	Statistical analyses lacking, critical and ethical discussion lacking, description of methodology partly lacking, eg, the number of invited members not mentioned	Low
Farhat et al 201638	Mainly logically presented methodology	Aim is not explicitly presented, number of physicians who responded not reported, results presented in table format only, critical discussion lacking	Low*
Felix et al 201433	Explicit aims	Strategic sample selection, details of the questionnaire form were not available, exact numbers of respondents which certain opinion (n) not always reported, description of used statistical methods and data analysis lacking, inconsistency in the description of results	Low
Reilly and Gewanter 201537	Explicit aims	Respondents from market research panel resulting that respondents work in disciplines in which do not necessarily involve biosimilars, such as psychiatry, description of used statistical methods and data analysis lacking, critical and ethical discussion lacking	Low
O’Dolinar and Reilly 201426	Explicit aims	Intentional sample selection, clear presentation of results lacking, critical and ethical discussion lacking	Low
Reilly and Murby 201735	Explicit aims	Description of data collection partly lacking, description of used statistical methods and data analysis lacking	Low

*Differences in opinions of which quality grade each publication was given, set in consensus.