Table 2.

Summary of eligible articles

Author, year	Methods	Participants; setting	Intervention/System	Barriers
Birmingham 2011 [32]	Focus group	21 pediatricians/nurse practitioners; New York, US	Computerized clinical reminders (CCRs) for influenza/electronic health records (EHR)	· Too much pop-up information makes it easy to ignore all alerts
				· Mixed confidence in reliability and accuracy of EHR alerts
				· Strongly opposed to alerts that interrupted workflow or forced an action before continuing documentation in a note
				· Concern that alerts will strain nursing staff
Clark 2006 [26]	Mail survey	756/1235 family physicians; 15 states in the US	Patient immunization history tracking for RR interventions/state immunization registry	· Too much cost/staff time
				· Insufficient technology assistance
Dombkowski 2007 [28]	Mail survey	389/600 pediatricians and family physicians; Michigan, US	Patient immunization history tracking for RR interventions/state immunization registry	· Accuracy of Medicaid data used to identify children with asthma and the potential restriction of the registry’s high-risk indicator to only Medicaid patients
				· Consistent access to the registry
				· Overall accuracy and completeness of registry data
				· Staff not accustomed to using registry to check patients’ immunization status
Deutchman 2000 [27]	Mail survey	158/250 family physicians with pediatric patients; rural Colorado, US	Patient immunization history tracking for RR interventions/no specific system	· Integration of new system into current computerized functions
				· Patient confidentiality
				· Costs, staff time associated with using the system to track patients
Fung 2004 [30]	Survey	261/1304 clinical staff or informatics experts from 142 Veterans Health Administration (VHA) facilities; US	CCRs including for immunizations/EHR	· Perceived utility of CCRs, training and personnel support for computer use, EHR functionalities and performance data feedback to providers at each facility
Humiston 2009 [33]	Focus groups	24 family physicians and nurses; New York, US	Patient immunization history tracking for RR interventions/no specific system	· Difficulties in identifying which adolescents were vaccinated, especially due to frequent moves
				· Neither EMR nor state registries are helpful given poor communication between school and primary care offices
Saville 2011 [31]	Semi-structured interviews	24 pediatricians, nurses and practice administrators from 11 practices; Colorado, US	Patient immunization history tracking for RR interventions/state immunization information system	· Difficulties overcoming the obstacle of inaccurate contact information
				· Perceptions of low compliance with recall notices for certain risk groups
				· Perceived conflicts in the immunization algorithms between registry and the practice.
				· Lack of dedicated time and personnel for recall activities
				· Inaccuracies both with patient contact information and immunization data in system;
				patient contact information was not routinely updated in system, only in EHR
				· Unmet expectations for responses to recall efforts can lead to method discontinuation
				· Extra time required to crosscheck recall with appointment schedules to ensure under-immunized patients have not already planned physician visit
Tierney 2003 [23]	Semi-structured interviews and surveys	18 clinician-administrators representing adopters and non-adopters; 912 (76%) pediatricians and public health staff completed surveys; US	Patient immunization history tracking for RR interventions/no specific system	· Both adopters and non-adopters of reminder or recall messages identified time and money as the most important barriers to implementing these methods.
				· Not having a simple way of identifying children at a specific age, review records or begin an initiative
				· Lack of knowledge about how to get started and limited computer skills were named as barriers by only 10% to 18% of respondents in any subgroup
Wallace 2004 [34]	Semi-structured interviews, questionnaires, group discussions	Clinicians at 23 Spinal Cord Injury (SCI) centers in the VHA; US	CCRs for influenza/EHR	· Lack of coordination between EHR and vaccination data so cannot be sure patient has not been vaccinated elsewhere unless extra work is done
				· Different forms (and locations) for inpatients and outpatients is frustrating for clinicians
				· Lack of training can result in inadequate information that is not useful
				· Lack of access for all immunization staff
Yarnall 1998 [29]	Survey	Physicians caring for a sample of 1314 study patients in a large community health centre*; North Carolina, US	CCRs including those for immunizations/computerized health maintenance system	· Lack of time
				· Additional workload as staff still need to use and complete paper maintenance forms

This table summarizes key details of the 10 articles included in the systematic review.

*Number of physicians not reported.