Table 1.

Strengths and limitations of quality assessment measures

Process measure of quality	Strengths	Limitations	Assessment level
Unannounced standardised patient	Standardised, controlling for case-mix and patient- mix; Unannounced, no Hawthorne effect (if not be detected); Reduced recall bias	Expensive Limited medical conditions First-visit bias Selection bias if informed consent is required	Action (Do) Gold standard
Clinical vignettes	Cost-effective; Suitable for large scale and cross-system comparison; Covering all illnesses; Accounting for case-mix and patient-mix.	Hawthorne effect Selection bias	Competence (Know how) Overestimating care quality (best answers) or similar
Virtual patients	Interactive Real-time response and automatic record Highly standardised Scalability and low marginal cost Efficient delivery: anytime, anywhere Suitable for large scale study	Hawthorne effect Selection bias High cost in initial development	Performance (Show how) ?