Table 1.

Summary of included studies

Author/s	Year	Location	Setting	Participants	Method	Objectives	Relevant findings
Busby, Matthews, Burke, Mullins and Schumaker	2015	UK	64 Dental practices (64)	10,810 Patients	Surveys	To investigate the relationship between perceived quality and patients' tendencies to recommend a practice to friends and colleagues.	NPS may provide broad but valuable insights into patient perceptions. Benchmarking is most useful within a particular sector.
Gerrard, Jones and Hierons	2017	UK	Primary care oral practices (3)	2019 Patients (Round 1) and 202 patients (Round 2)	Surveys	To test the suitability of PREMs and PROMs surveying.	Staff reported that NPS surveying was time‐consuming and resource‐intensive. NPS (FFT) is subject to various biases. Data should be used for local analysis and improvement, rather than as a comparison between providers.
Hamilton, Lane, Gaston, Patton, MacDonald, Simpson and Howie	2014	UK	Orthopaedic centre (1)	6186 Patients	Surveys	To quantify NPS for joint replacement and ascertain how care is benchmarked against nonhealthcare services, and assess which factors influenced the patients' recommendation response.	There were high rates of completion for recommendation questions. Case mix should be taken into account when comparing scores between hospitals and departments. NPS differences between procedures suggest no overarching score should be given without case‐mix adjustment.
Koladycz, Fernandez, Gray and Marriott	2018	India, Kenya, Nigeria and El Salvador	Family planning clinics	188 Patients in Mumbai, 590 patients (in nine clinics) in Kenya and Nigeria, and 226 patients (in three clinics) in El Salvador	Surveys and interviews (face‐to‐face and telephone)	To test the feasibility and acceptability of implementation approaches in low‐resource clinical settings; to assess whether the methodology could be used to generate meaningful comparative information about the experience of different client groups; and assess the feasibility of a self‐administered NPS using tablets.	Clients (in India) understood the NPS question without additional explanation. Participants may feel challenged to offer suggestions for improvement. Targeted feedback may be necessary to identify actions for improvement, including asking specific questions. Staff reported that NPS was easy to complete. NPS can be used effectively in low‐resource settings with low literacy.
Krol, Maarten W.; Boer, Dolf; Delnoij, Diana M.; Rademakers, Jany J. D. J. M.	2015	The Netherlands	Acute hospitals (6)	6018 Inpatient surveys	Surveys	To assess what the NPS adds to patient experience surveys, and to establish whether NPS is a valid measure for summarizing patient experiences.	Patient experience had a weaker association with NPS than global rating and overall score. NPS is less valid as a summary of patient experience than a global rating. Patients thought it was unusual to recommend healthcare. NPS may oversimplify results, so should be used as an addition to the survey results.
Lawton, O'Hara, Sheard, Reynolds, Cocks, Armitage and Wright	2015	UK	Hospital wards (33)	822 Patients and 648 staff	Surveys	To investigate whether the safety information provided by patients is different from that provided by staff, and whether it is related to safety outcomes.	NPS was associated with patient perceptions of safety, but not associated with safety outcomes. Patient Measure of Safety may be a better indicator of patient safety than NPS.
Manacorda, Erens, Black and Mays	2017	UK	General practices (40)	118 Staff, with clinicians, practice managers and patient representatives	Semi‐structured interviews	To examine the views of practice staff and patients of NPS (FFT), how results are used and to recommend improvements.	NPS questions may be inappropriate (e.g., due to limited choice for GP, and lack of detail in answers to explain reasons). 4 of 42 GP clinics expressed positive views about the use of NPS; only one clinic provided an example of how results had improved quality. NPS is easy to implement, but data had minimal impact on quality improvement. Suggest removing NPS questions and providing a more targeted, specific survey.
Marsh, Peacock, Sheard, Hughes and Lawton	2018	UK	Hospitals	Database search	Scoping review	Review and categorize the types of patient experience feedback data available to understand their function in quality improvement.	Hospitals are challenged to manage the volume of mandated feedback. Mandated patient experience data (including FFT) offers little ready‐to‐use data for quality improvement.
Medforth and Rooksby	2017	UK	General and dental practices (8)	Children	Survey review and case study	To use quantitative data from the Children and Young Person Friendly Friends and Family Test (CYPFF) to assess the impact that the CYPFFT resources have on the uptake of the FFT by children and young people.	NPS was perceived as simple and can be used by children with special needs. NPS survey was completed by a wide range of ethnicities. NPS survey is useful but may add an administrative burden. NPS may raise awareness about the importance of feedback.
Sizmur, Graham and Walsh	2015	UK	Hospitals (32)	38,998 Inpatients and 29,610 ED attendees	Secondary analysis of data collected	To investigate the impact of demographic factors and the mode of administration of a national patient experience questionnaire (FFT).	NPS (FFT) is vulnerable to bias from demographic factors and mode of administration.
Stirling, Jenkins, Clement, Duckworth and McEachan	2019	UK	Centre for hand surgery (1)	810 Patients	Surveys	To quantify NPS for specific hand surgery, identify contributing factors and evaluate the suitability of NPS as an outcome measure for hand surgery.	NPS varied from 44 to 83 for different hand surgeries, which provides a comparison between surgery types. NPS is a useful addition to support the evaluation of clinical value.
Wilberforce, Poll, Langham, Worden and Challis	2018	UK	Mental health teams for older people	352 Respondents	Surveys	To explore the value of NPS as a service improvement tool and outcome measure.	NPS was negatively related to age. NPS may produce value if part of wider data collection, and with a larger sample of service users. Caution is needed when comparing NPS from patients with different prognoses. It may be better to develop a quality score from multi‐item measures, which would provide more breadth and improved reliability.

Abbreviations: FFT, Friends and Family Test; GP, general practitioner; NPS, Net Promoter Score; PREM, patient‐reported experience measure; PROM, patient‐reported outcome measure.