Background: Healthcare quality is multidimensional and should be measured from a multistakeholder perspective. Experiential knowledge from patients, kin and professionals is increasingly recognised as contributions in quality management considering the trend towards value-based, co-produced healthcare systems. To address this gap in existing research, we aimed to develop and validate a new instrument.
 Methods: Content validity was established using a multidimensional quality model validated by four focus groups with patients and kin and two with primary care professionals. To obtain face validity, a multistakeholder group (n=41), including patients, kin and professionals, pilot-tested the mirrored instrument ‘FlaQuM-Quickscan’ measuring ‘Healthcare quality for patients and kin’ (part 1) and ‘Healthcare quality for professionals’ (part 2). Each instrument part contains 15 quality items and 3 global ratings. A multicentre study with 17 Flemish (Belgian) hospitals was conducted to perform other validity tests, including construct validity by factor analyses across type of respondents, criterion validity by item-to-general-items correlations and a process evaluation by conducting semi-structured interviews.
 Results: In total, 13,615 respondents (N Patients/kin = 5,891, N Professionals = 7,724 and N Primary care = 454) completed the FlaQuM-Quickscan. The confirmatory factor analyses showed reasonable to very good fit for part 1 ‘Healthcare quality for patients and kin’ (scored by patients/kin: CFI = 0.961, TLI = 0.951 and RMSEA = 0.084, scored by professionals: CFI = 0.950, TLI = 0.938 and RMSEA = 0.080, scored by primary care: CFI = 0.948, TLI = 0.935 and RMSEA = 0.101) and for part 2 ‘Healthcare quality for professionals’ (scored by patients/kin: CFI = 0.969, TLI = 0.962 and RMSEA = 0.085, scored by professionals: CFI = 0.946, TLI = 0.932 and RMSEA = 0.091, scored by primary care: CFI = 0.922, TLI = 0.902 and RMSEA = 0.129). The configural and scalar invariance were demonstrated across type of respondents and their characteristics. Correlations supported the associations between 15 instrument items and 3 global ratings for both instrument parts. The process analyses showed that addressing individuals directly and supportive technical structures to immediately complete the instrument were most effective to motivate respondents. 
 Conclusion: The FlaQuM-Quickscan is assessed as a valid instrument to measure healthcare quality experiences from a multistakeholder perspective. Integrating different perspectives gives the opportunity to analyse and gain understanding in experiences of stakeholders and reinforces a more holistic, well-informed approach towards quality. 
 Practice implications: This new instrument offers unique and detailed data from a multistakeholder perspective to co-produce a shared quality vision in organisations, to build a future sustainable quality management system and to set priorities on managerial and board level.
 Next steps: Future research will assess the transferability to other healthcare systems, examine variation between stakeholder groups and organisations and support to set quality priorities on managerial and board levels.