We report findings from a multi-center survey conducted to support quality improvement efforts to address ambulatory diagnostic problems faced by primary care physicians. We elicited several cognitive factors PCPs believed to be associated with diagnostic delays, as well as strategies for improvement. We found that half of respondents reporting that more than 5% of their cases were difficult to diagnose. Though this is not a high proportion for any individual clinician, it represents many difficult diagnoses overall. In our analysis, diagnostic difficulty appears to correlate with inadequate time to process diagnostic information and insufficient guidance from subspecialists.
Our study provides rich data regarding processes of care that make diagnosis vulnerable to errors in the primary care setting. Cognitive factors including inadequate knowledge base and faulty perception/detection were noted, but even when specifically asked about cognitive factors, respondents referenced system and patient factors, underscoring their importance. The most frequent cognitive factor reported was related to inadequate knowledge, in contrast to a previous study where knowledge problems were only infrequently related to diagnostic errors16
. This was followed by faulty detection or perception of diagnostic information (such as from history/exam/record review), a factor also prominent in a recent survey of pediatricians19
. In addition to improving information synthesis and reducing errors from biases and heuristics, efforts to reduce diagnostic errors should also focus on these two important factors. As with prior studies4,7
, lack of timely information review was commonly cited as a contributor to missed and delayed diagnosis.
We also report specific improvement strategies that primary care physicians believe will improve missed and delayed diagnosis, for which empiric literature is generally lacking. Respondents' strategies for improvement often centered on physician workload; they identified several distinct links between physician workload and delays in diagnosis. First, they perceived longer visit time with patients, which may allow for more thorough history and physical examination, as important to the diagnostic process. Second, they specifically cited reducing workload in order to have protected time to review patient results, to ensure follow-up of clinical abnormalities. Other recent studies also demonstrate this to be a high-risk area despite improved information availability.20,21
For instance, studies reveal sub-optimal follow-up of abnormal test results, even in the presence of electronic health record-based clinician notification, suggesting that that missed or delayed diagnoses are not always related to lack of access to information. Other system and cognitive factors including time and workload are likely in play and need to be targeted for improvement.
In addition, participants suggested more time for physicians to think carefully about difficult cases, and to perform “cognitive work”.22
Moreover, they cited the burden associated with non-visit-related tasks. These tasks, such as following up patient test results, are increasingly becoming recognized as a significant contributor to physician workload,23
and will require specific, workflow targeted efforts to address. It is possible that the patient-centered medical home model, 24
with panel-based rather than visit-based reimbursement, 25
will allow for clinicians to allocate their time in a way that better supports timely, correct diagnoses. As an example, in the integrated health system in which this study took place, assessment of PCP performance is shifting to quality, service, and access metrics across a PCP's patient population, rather than the measurement of the number of visits per day provided by the PCP.
Despite the presence of an integrated health care system where subspecialists were readily accessible, we found that the referral process is perceived as a barrier to timely and complete diagnosis. The PCPs in this study who reported diagnostic difficulty acknowledged problems accessing and communicating with subspecialists. This problem is likely be worse in individual practices, where PCPs interact with subspecialists from several other health care systems using many types of communication methods.26
In addition, the issue of shared responsibility for a patient between a subspecialist and a PCP merits further inquiry. For instance, there is no clear consensus among clinicians about who should refer patients to a second specialist if the first specialty referral does not result in a diagnosis and/or treatment plan.27
Similarly, physician perceptions vary about who should inform patients about abnormal test results; studies suggest that usual clinic practice leaves many patients uninformed.18
Some degree of standardization of referral expectations and practices is likely to enhance the diagnostic process.26
Our study has several limitations. First, although conducted across five distinct U.S. geographic regions with significant variability in practice settings, it was originally designed as a quality improvement project within a single health system with salaried, staff physicians and thus, its generalizability might be limited. For instance, it might not be representative of communication between PCPs and subspecialists in U.S. ambulatory health care in general where per-consultation financial incentives for subspecialists are different.28
Second, our study was performed in 2005
. Findings remain relevant despite the age of the data because: (a, cognitive factors described here are unlikely to have substantively altered; (b) system factors such as short visit length and problems processing information from multiple inputs are likely to persist. However, this study was conducted prior to comprehensive electronic health record (EHR) implementation at this health system. Barriers we found associated with perceived difficulty might not necessarily be mitigated by EHRs29
and most U.S. primary care practices do not currently have a comprehensive EHR. Third, this study was conducted prior to many of the landmark studies on diagnostic error and diagnostic processes; thus, the phrasing of the items might not at times follow taxonomies laid out in these papers4,7,16,30
. However, the issues described in the survey are interpretable, have been described in the literature, and emanate from primary care workflow. Fourth, the patient population cared for by the PCPs, although demographically diverse,31
represents a group with health insurance, mostly provided by employers. As such, patients in this system may have fewer barriers than in other ambulatory health care settings. Fifth, our results reflect only the missed diagnoses that providers are aware of. There are likely other missed diagnosis that remain unknown to primary care providers, and our study cannot shed light on this type of missed diagnosis. Finally, as with all survey research, subjects who chose to respond to the survey are likely to differ from those who do not. We did not have sufficient demographic information on non-responders to make inferences about how non-response affected the reported results.
In summary, a significant proportion of primary care physicians report diagnostic difficulty involving at least 5% of their patients. Misdiagnosis relates to several system and cognitive factors but knowledge gaps might be more often responsible than previously estimated. Interventions that address practice level issues such as time to process diagnostic information and better subspecialty input might potentially reduce diagnostic safety concerns in primary care.