Original Research

Unexplained complaints in primary care: Evidence of action bias

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When patients present with symptoms that do not fit a recognizable diagnostic pattern, testing—although often unnecessary—is preferred by primary care physicians.




Purpose Primary care physicians sometimes encounter patients with clinical complaints that do not fit into a recognized diagnostic pattern. This study was undertaken to assess the way physicians respond to patients whose symptoms are unusual or unexplained—that is, what approach they take in the absence of a working hypothesis.

Methods We surveyed 130 primary care physicians affiliated with 3 academic centers in Israel, presenting 5 clinical vignettes describing patients who had unusual complaints, no clear diagnosis, and no apparent need for urgent care. We asked physicians to provide the most likely diagnosis for each case and to rate their level of confidence in that diagnosis;respondents were also asked to provide a management strategy for each case and their level of confidence in the chosen approach. Finally, we asked the physicians to estimate how many of their own patients have presentations similar to the individuals in the clinical vignettes.

Results Physicians proposed, on average, 22 diagnoses for each case. Most indicated that they would choose action (testing, consulting, sending the patient to the emergency department, or prescribing) rather than follow-up only (87% vs 13%; P<.01). Respondents’ confidence in the management approach they had chosen for all the cases was higher than their confidence in the diagnoses (5.6 vs 4.3, respectively, on a scale of1-10; P<.001). Physicians estimated that 10% to 20% of the patients they see in their practice have unusual or unexplained symptoms that are difficult to diagnose.

Conclusion Uncertain diagnosis is a regular challenge for primary care physicians. In such cases, we found that physicians prefer a workup to follow-up, an inclination consistent with“action bias.”

Physicians in primary care sometimes encounter patients with clinical complaints that do not fit into a recognized diagnostic pattern.1 There are varying reports of the prevalence of such cases, ranging from ≤10% when stringent definitions of medically unexplained symptoms are used2 to as high as 40% to 60% of visits.3,4 Unexplained complaints, which may or may not be related to psychiatric disorders, can significantly contribute to high consumption of health care resources.5 Uncertain diagnoses are associated with increased testing6 and false-positive results, which often lead to more tests and complications.7

When physicians face medically unexplained symptoms, their behavior often differs from the watchful waiting approach some recommend.6 This behavior has been attributed to various factors, such as fear of litigation, greater concern about omission than commission, and perception of patient expectations.5 A study involving young patients suggested bias toward intervention for common pediatric diagnoses.8 Using a similar design of physician responses to clinical vignettes,we sought to evaluate a potential bias toward action, such as testing or referral, for patients with unexplained medical complaints.


Over several months, 2 of us (AK, IG) identified 60 patients in our practices who had(1) unusual medical complaints, (2) no clear diagnosis, and (3) no apparent need for urgent care. After careful consideration, our team selected 5 cases that best fit the above criteria and reflected the widest spectrum of clinical presentations encountered in primary care settings. After removing identifying patient information, we wrote each case up as a clinical vignette, then presented all 5 cases to primary care physicians affiliated with 3 major academic centers. For each case, respondents were asked to provide:

  • the most likely diagnosis and their level of confidence in that diagnosis (on a scale of 1 [no confidence] to 10 [complete confidence])
  • a management strategy (testing, consulting with a specialist, referral to the emergency department [ED], prescribing medication, or follow-up only) and their level of confidence in that choice.

Physicians were asked to estimate the frequency of such cases in their practice, as well.

Preparation of the data (cleaning, sorting, and filtering) was carried out using JMPv9.0 (SAS Institute, Cary, NC), and analyses were conducted with SPSS v19.0 (IBM,Chicago, Ill). We used descriptive statistics to represent the data and chi-square and ANOVA to compare physicians’ decisions(action vs follow-up). Nonparametric tests were used to compare levels of confidence for diagnosis and management.


We surveyed a convenience sample of 130 primary care physicians affiliated with academic medical centers, 100 of whom responded. Most respondents (62%) were female, and 86% were certified in family medicine. The average age was 45 years (range 30-68 years),with a mean time out of medical school of 17 years (range 1-26 years). Respondents were born in 14 different countries and had undergone medical training in Europe, the United States, or Israel. The diagnoses and management approaches selected for each clinical vignette are presented in TABLE 1. For each case, an average of 22 diagnoses (range 18-25) were proposed. Most physicians (87%; P<.01) indicated that they would choose some type of action (testing, consulting, sending the patient to the ED,or prescribing medication) rather than follow-up alone (TABLE 2). Respondents were able to choose multiple management There appears to be a stronger perceived need to “do something” than to engage in watchful waiting and follow-up.strategies. For all 5 cases, the physicians had more confidence in their patient management approach than in their diagnosis (5.6 vs 4.3;P<.001). On average, men had higher levels of confidence than women for both diagnosis and management (P<.05). Other demographic characteristics, including age, experience, certification, and site of training, were not predictive of confidence level. Respondents estimated that 10% to 20% of their own patients present with unusual and unexplained symptoms, like the patients in the clinical vignettes.

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