Failure to follow up test results is a critical safety issue which has been identified as a major problem in ambulatory settings.14 The practices and processes currently used are varied and unsystematic2,5 and physicians6,7 and patients8,9 acknowledge that this needs to improve. The testing process in ambulatory settings is complex and can be divided into three broad phases, pre-analytic, analytic and post-analytic (Fig. 1), each involving multiple steps and multiple personnel including clinicians, patients, office and laboratory staff.10

Figure 1.
figure 1

Conceptual framework of the testing process (Source Hickner et al. 2008, p.195).10

Figure 2.
figure 2

Search flow for failure to follow-up test results for ambulatory patients, including keywords and MeSH terms used in search process.

Most primary care practices are not using electronic health records,11 and most are communicating with multiple laboratories often not electronically connected.12 Increased volumes of tests and the time consuming nature of test follow-up places further pressures on physicians.6,13,14 Failure to follow-up can lead to missed or delayed diagnoses which impact on patient care13,1517 and can also have medico-legal implications for health services and health professionals.1821

Without knowledge of the size of the problem, many clinicians may underestimate its extent and therefore fail to take any action to improve the process.22 Feedback on medical errors is essential to negate overconfidence in decision making in relation to diagnostic accuracy.2225 Ambulatory settings pose specific challenges for effective test management in addition to many of those present in acute care settings.26 There have been no systematic reviews in this setting, and therefore the aim of this paper was to review evidence which quantifies the size and impact on patient outcomes of failure to follow-up test results for ambulatory patients.


Data Sources and Searches

Medline, CINAHL, Embase, Inspec and the Cochrane Database were systematically searched for English language articles published between 1995 and November 2010 which quantified diagnostic tests not followed-up (Fig. 2). Search terms were identified from keyword lists of core articles related to the topic. Reference lists of articles which met the inclusion criteria were hand searched. A web search using the Google Scholar search engine was completed to locate un-indexed publications.

Study Selection

Included were studies which quantified failure to follow-up laboratory and radiology tests for patients attending ambulatory settings including: outpatients, patients treated at academic medical and community health centres and attending primary care practices. Failure to follow-up a test result was defined as the ordering physician or another provider neglecting to document follow-up action(s) relating to a test result. Excluded were studies reporting physicians’ or patients’ perceived rates of failure, time from placement of test order to treatment, analysis and reporting of test follow-up for inpatients and outpatients combined27,28 and studies on individual patients.

Data Extraction

Four reviewers (JC, AG, JL, JW) each independently reviewed all articles for inclusion. Discrepancies among reviewers were resolved by discussion until a consensus was reached. Data extracted included: test type, indication of failure to follow-up, systems used, extent and patient outcomes.


The literature search yielded 768 references (including four from hand searching) from which 19 articles were eligible (Table 1).

Study Characteristics

All studies were conducted in the United States. The majority of study designs used retrospective medical record reviews (n = 16)2,2943 to provide documentary evidence of test follow-up. Other methods were: retrospective linkage of databases (n = 1),44 retrospective review of malpractice claims for missed or delayed diagnoses (n = 1),45 and a prospective longitudinal medical record review (n = 1).46 Most studies focused on lack of follow-up of abnormal laboratory tests only (n = 11).29,32,3538,4145 Four studies investigated lack of abnormal radiology follow-up only31,39,40,46 and another four studies included lack of follow-up for both laboratory and radiology test results.2,30,33,34

Extent of Failure to Follow-up

There was wide variation in the rates of missed abnormal laboratory results ranging from 6.8% (79/1163)41 of alerts displayed through a computerised provider order entry system which were not followed-up within 30 days to 62% (125/202) of abnormal glucose tests not followed-up.32 Similarly, for abnormal radiology, lack of follow-up ranged from 1.0% (4/395)31 of patients with suspected malignancy to 11% (131/1196) of critical imaging alerts.40 The two studies on mammograms reported 11% (9/82)30 and 35.7% (45/126)46 with no evidence of patient follow-up. Even studies which focused on the same diagnostic tests showed a broad range in the extent of lack of follow-up: glucose testing32,35,44; abnormal FOBT,29,43 and TSH.41,42

Impact on Patient Outcomes

The impact of missed test results on patient outcomes were reported in seven of the 19 studies.29,31,32,38,40,42,45 Missed cancer diagnoses were reported in four.29,31,40,45 Other reported outcomes were increased visits to hospital as a result of hyperkalaemia related to missed abnormal serum potassium levels38 and adverse drug events related to insufficient supplementation with levothyroxine due to missed follow-up of abnormal TSH results.42 Patients who received appropriate follow-up of diabetes screening were more likely to have been scheduled for follow-up appointments than those who were not (92% versus 66%, P = 0.001) and were also more likely to have kept the appointments (90% versus 58%, P = 0.001).32

People and Policies

Test management involves information communication between many individuals across care settings including: physicians, nurses, clerks, laboratory staff, and patients. Studies showed that test follow-up practices varied between individuals34,37 and practice settings.33 Individuals other than physicians were involved in the test follow-up phase, including nurses and practice managers.2931,33,34

Several studies reported an absence of guidelines regarding who has responsibility, and how and when to notify patients of results.2,29,33,34 Singh et al. in 200739 showed lower rates of missed abnormal imaging results than similar studies which they concluded was associated with having standardized processes and procedures for abnormal test result follow-up in combination with an electronic test result notification system.

Systems Used for the Test Management Process

Those studies which described the systems used to deliver test results to physicians and how follow-up was documented ranged from paper-based medical records with test results delivered in hard copy2,29,30,33,34 to electronic medical records (EMR) with results transmitted electronically,2,33,34,3941 or a combination of paper-based medical records and electronic or part-electronic test management systems.2,31,37,38 Evidence of the effectiveness of electronic test management systems to reduce missed follow-up was limited to five studies.2,34,3941 Although these evaluations were not pre/post control studies they showed a general trend towards improved test follow-up in ambulatory settings which used electronic systems.

Three studies evaluated whether an automatic alert system for notification of abnormal results resulted in timely follow-up of radiology39,40 and laboratory tests.41 Even though these studies have some features which may limit generalisability, due to the unique characteristics of the Veterans Affairs (VA) population (predominantly male veterans), the home-grown EMR VA system, and the lack of pre EMR data for comparison, results showed that the rates of loss to follow-up appeared lower than those reported in sites that do not use information technology. However, even with the sophisticated electronic alert system in place a proportion of results were still missed: 4% (45/1017) of critical imaging results39; 11% of alerts for abnormal imaging (acknowledged and unacknowledged)40; and 6.8% of specified abnormal laboratory tests.41 Interestingly, in the latter study Singh et al.41 found that 10.2% of alerts were unacknowledged by physicians (provider did not click on and open the message within two weeks of transmission) and timely follow-up was statistically not different for acknowledged and unacknowledged alerts (6.4% versus 10.1%; P = 0.13).

Having test management processes supported by hybrid paper and electronic systems has also been shown to create problems with test follow-up. Casalino et al. reported that the use of a partial electronic medical record (paper based progress notes and electronic tests or vice versa) was associated with higher follow-up failure rates compared to relying entirely on paper-based systems (OR 1.92; P = 0.03) or compared to having a complete electronic record that included both progress notes and test results (OR 2.37; P = 0.007).2 Another study found that results managed in the EMR were significantly better documented than those with paper (40%, 33/82, compared to 64%, 57/88, p = 0.001)34 and documentation of follow-up actions has been shown to impact positively on test management.38,46


Extent and Impact on Patient Outcomes

Failure to follow-up test results occurs frequently in ambulatory settings and evidence of its impact demonstrates that it is an important patient safety issue which needs urgent attention. There was wide variability reported regarding the extent of the problem ranging from 6.8%41 to 62%32 for missed laboratory tests and 1.0%31 to 35.7%46 for radiology. This variability was also present in studies which examined follow-up of the same test types which highlights the heterogeneity of the studies and the complexity of the problem.29,32,35,4144 Similar results relating to extent and variability of test follow-up have previously been reported for inpatients (20.04%–61.9%) and patients attending emergency departments (1%–75%).26 Impact on ambulatory patient outcomes were considerable and included missed cancer diagnoses29,31,40,45 underpinning the urgent nature of the problem and the need to evaluate solutions.

Given that all studies were conducted in the US care should be taken in generalising the findings to other countries although anecdotal evidence suggests that test management practices are similar worldwide. Eight of the 19 studies were based in three sites and undertaken by the same lead researcher in each site.33,34,3641 A limitation of 12 of 19 studies was that they were conducted in single sites. However the six studies which included multiple primary care practices with large samples showed consistently high rates of lack of follow-up.2,30,3234,46 Most studies used retrospective medical record reviews which may result in an overestimation of the problem as some results could have been followed-up even though the physician failed to document the action. It is possible that there may be some publication bias whereby papers which reported higher rates of missed follow-up of test results are more likely to be published than studies which found low rates.

Missed test results in ambulatory settings are attributable to multiple factors including: the paucity of governance principles related to test management; the lack of integrated information systems around test management; the multidisciplinary nature of test management processes, and the need to consider the role of the patient in test result follow-up.

Test Management Governance Principles

There are few standard policies or procedures for test result management in the literature or within ambulatory practice organisations. This contributes to the variability of responsibility and the diversity of work practices around each of the steps in the test management process.2,29,33,34,39,40 Singh et al.39 concluded that if policies and procedures were in place, combined with the use of an electronic alert notification of abnormal radiology, then follow-up of results would be improved. However they found that missed results were not eliminated altogether39 indicating the complex nature of the problem and the need to consider a combination of interventions.

The lack of clear lines of responsibility for follow-up is further complicated by the number of people involved. Blurred lines of responsibility were evident in one study which evaluated the practice of dual-alert notification: this measure was adopted as a safeguard and entailed communicating the alert of an abnormal radiology result to two recipients, for example the hospital doctor who ordered the test and the primary care physician.40 Results showed that dual-alert notification significantly increased the odds that the alert would not be read and receive timely follow-up action (OR, 1.99; 95% CI, 1.06–3.48).40 This highlights the need for explicit guidelines regarding responsibility and timeframes for follow-up.

The Role of Information and Communication Technology in the Process

Although studies of evidence regarding the link between EHRs and ambulatory quality of care have shown mixed results,4751 a number have shown that information and communication technology (ICT) can play an important role in ensuring a safer and more systematic test management process.1,52,53 The five evaluations of the impact of ICT on missed test results, included in the review, provided evidence of a favourable trend towards reduced missed results.2,34,3941 The use of ICT facilitates communication flow between individuals across care settings and has been shown to improve documentation38,46 all of which are crucial for the test management process. Other studies have shown that ICT can support and enhance the test management process14,5457 with acknowledgement of receipt of results and documentation of follow-up action and patient notification recorded in an EMR which can be securely accessed by multiple health professionals.

Timely communication is vital and can be particularly challenging for ambulatory patients given the many individuals and settings involved. Information transfer about tests ordered and results received can have multiple points of communication breakdown: between inpatient and outpatient settings16,36; between laboratories and physicians58,59; between physicians and other member of their team33,34; and between physicians and patients.9,60 Electronic systems are an essential component of any solutions, however, they need to be integrated into the context of ambulatory settings and the way health professionals work.61,62 Financial issues are also considered to be a key barrier to primary care physicians’ use of EHRs and financial incentives will be a key lever for improving uptake.11

Technological solutions are not the entire answer as studies show that even with the use of an EMR with computerised notification of abnormal results using an alert every time the provider logs-on, abnormal results can still be missed.3941 Even though physicians can electronically acknowledge that they have opened an alert message this does not necessarily indicate they have read and acted upon the abnormal result.41 Appropriate follow-up requires the physician to review the result, communicate this to the patient, decide on an appropriate plan and discuss this with the patient and help them with that follow-up plan.46

Electronic discharge summaries have been shown to improve quality and timeliness of information including test results.63 However, there can also be problems as electronic discharge summaries may not always reach the family doctor64 and may not include all the necessary clinical information required for the ongoing treatment of the patient.65,66 There can also be an overreliance on ICT. One study reported that staff who used an EHR believed that electronically reported results did not get lost and were unaware that several tasks still depended on individuals.33 Thus, even with an EHR there can still be weaknesses in test tracking.56

Multidisciplinary Nature of Laboratory and Radiology Test Management Processes

Test result follow-up and patient notification in ambulatory settings are generally undertaken by the physician treating the patient, with involvement of other physicians, nurses, laboratories, and practice managers. A number of studies recommend the need to take account of the multidisciplinary nature of the test management process and include not just the physician who ordered the test but other ambulatory practice staff30,40 and also laboratory staff,67 in the design of solutions.

The involvement of nurses in the test notification process is evident in a number of studies29,31,33,34,37 and in busy ambulatory settings, where follow up of results is time consuming,13,14 this would seem to be a valuable approach. Nurses were reported as having a positive impact in one study where there was no significant difference between physicians and nurse practitioners in appropriate documentation of follow-up (p = 0.61).31 Studies have shown that documentation was associated with the delivery of appropriate46 and with timely follow-up of test results.38 Clerical staff in ambulatory settings can also assist in the follow-up of test results particularly in relation to ensuring systems are in place to alert physicians to results returned from laboratories and in the patient notification stage of the process.33

An innovative work practice change is the suggestion that radiology staff should become more involved in the patient test notification process.67,68 The process of direct patient notification by the radiologist has been described by one Imaging Service in the US whereby patients’ are given a card on arrival asking if they would like to receive preliminary results of their examination.69 If the patient agrees the radiologist documents the preliminary results on the card which is given to the patient before they leave the Imaging Centre.69 Currently there are guidelines for direct communication of critical imaging findings by radiology staff to ordering physicians.70 However, problems arise in ensuring critical results are communicated to the appropriate person.16,31,71 Singh et al.40 found that verbal communication by radiology staff in addition to electronic communication of results strongly predicted timely response and follow-up, however this was probably because the radiologist called only for life threatening findings. Solutions which acknowledge the inter-dependence between physicians, nurses, and radiology/laboratory staff are important to ensure the safe communication of abnormal test results.72

The Role of the Patient in Test Result Follow-up

There have been suggestions that patients can play a role in detecting and preventing medical errors73 and could therefore have an enhanced role in the test result follow-up process.2729 Direct notification of test results to patients could serve as a safety net for providers and empower patients to be partners in their care.8,9 It is possible for electronic systems, linked to test result databases, to generate automatic letters, email or telephone messages to notify patients directly of positive and negative test results9 or to allow patients’ direct access to results via a patient portal.74

The issue of direct patient notification however, is complex and many factors need to be considered. Physicians have expressed concerns including: whether an abnormal result will alarm a patient unnecessarily; receipt of an avalanche of contact from worried patients; practice variations in timing of patient notification; malpractice risks; and an increase in un-reimbursed tasks.74 There are few published studies in this area, however, a feasibility study to introduce on-line laboratory results to patients in two primary care practices with 10 physicians reported that physicians had no increase in messages from their patients about inconsequential results showing that fears of unnecessary patient alarm may be unwarranted.74 If all patients are directly notified of their test results, they need to be able to read and understand the result and its implications.30 Patient understanding of test results could be enhanced by access to relevant online information sources with one study reporting 50% of patients who viewed results via a patient portal accessed reference information linked to the result.74

Whether patients hear their results verbally or receive them in hard copy can also impact on their understanding and the emotional state of patients receiving significant results may also impair their ability to digest information provided verbally.75,76 Poon et al.46 found that a significant proportion of women whose physician documented that they had discussed the test result with the patient did not recall the discussion, highlighting the need for patients to have a written record of their results. Direct access to results via patient portals where patients could print a copy of the result would ensure they had an accurate hard-copy of the result which could be used as a memory aid. It is now a US FDA requirement under the Mammography Quality Standards Act (MQSA 2004) that a summary of the written report in terms understandable by a layperson is sent directly to the patient within 30 days,77 however studies have shown that giving patients their results is not in itself enough to ensure that patients follow-up on the result.46,78 Physicians need to have an active role in follow-up to ensure the plans are understood by patients. Further work needs to be undertaken in this area to test the feasibility and effectiveness of strategies which enable patients to receive their test results automatically.


There are significant safety issues in the management of laboratory and radiology test results for ambulatory patients. Studies show that factors associated with failure to follow-up test results in ambulatory settings are complex and often it is a combination of elements, systems, people, organisational factors and work practices interacting that leads to important results being missed. This concords with patient safety research which has progressed to acknowledge the multi-factorial nature of medical errors and the need to address people and system factors if improvements are to be realised.7981 Solutions need to be multipronged and include: explicit policies, procedures and responsibilities for test follow-up; consideration of the role of others in the process including the patient and laboratory and radiology staff; evaluation of ICT solutions; and integration of solutions into the work practices of health professionals and into the context of health care delivery.