To make no mistakes is not in the power of man; but from their errors and mistakes the wise and good learn wisdom for the future. —Plutarch
*Mr. Ketterman's Case
Mr. Ketterman has a fairly unstable cardiac status. If I push him too hard, I could risk a serious cardiac event; if I don't push him hard enough, I will be increasing his morbidity. I don't want to make either mistake. (See Appendix for Mr. Ketterman's health history)
We all hope we have chosen health care practitioners who have a good amount of expertise, who can get things right. The issue of a practitioner's clinical expertise has been reinforced as crucial to good decision making by authors throughout the development and implementation of the evidence-based medicine movement. Straus et al1 define the clinical expertise element of evidence-based medicine as "the ability to use our clinical skills and past experience to rapidly identify each patient's unique health state and diagnosis, their individual risks and benefits of potential interventions, and their personal circumstances and expectations."1, p1 Similarly, physical therapists must make important choices in practice not only in determining the correct diagnosis and intervention but in performing many hands-on interventions, predicting outcomes of care, setting goals with patients and families, and coordinating resources and personnel to maximize the functional outcomes for the patient. Expertise in all these elements of practice reassures us that our physical therapist will also make good decisions regarding our care and get things right.
However, in clinical practice we all acknowledge that sometimes things don't go right. Sometimes cognitive skills, manual skills, and past experiences are insufficient for the task at hand. In these situations, clinical practice errors of varying magnitudes can occur. Of course, poor outcomes in clinical practice can also occur in a random fashion, as biological events are probabilistic in nature. More often, errors occur when the current level of scientific knowledge used to inform choices is inadequate, or when the clinician lacks knowledge, violates the patient trust in a purposeful manner, or uses faulty logic. Whatever the cause, an examination of clinical practice errors provides a source of knowledge to help us improve our level of practice.
Providing physical therapy care in a manner that reduces errors and increases patient safety should be the goal of every clinician, but it is not an easy goal to attain. Weingart2 states that the 1999 Institute of Medicine report To Err is Human3 provided evidence that medical errors pose daily risks throughout the health care system in this country but also elucidated the difficulty in estimating the magnitude and attribution of these risks. While injury of various types may occur to patients under our care, determining that these injuries are a result of clinician error is a complicated process. Weingart2 suggests that harm can result from many complex factors, including: the natural history of the patient's disease, comorbidities, the risks or negative effects of selected interventions, clinical misjudgments, technical performance errors, and bad luck. Given this complexity, it is not surprising that independent reviewers of patient safety events are able to identify when a harmful event has occurred but are not good at analyzing the degree of harm caused in the event nor if the event is a result the presence of a medical error.4
In this chapter we will provide an overview of research on errors in medicine, physical therapy, and occupational therapy. An understanding of the type, frequency, causes, and harm associated with errors is a good first step in our attempts to increase patient safety. We will examine errors and the causes of errors, for example, faulty clinical reasoning. In the previous chapter we identified the typical reasoning strategies used by physical therapists in making many types of decisions. Here, we will focus on learning how we might categorize and learn from errors of clinical reasoning. Our increasingly complex health care system can contribute to a clinician's sense of uncertainty when the clinician is making difficult decisions. The ability to recognize those situations in which our uncertainty is heightened should be an important component of reflection in our clinical reasoning process.
DESCRIBING MISSES AND MISTAKES IN HEALTH CARE
Although bad medical outcomes that happen to famous people garner much public attention, researchers find that good epidemiological data on errors is limited. Weingart et al5 report that the majority of information on medical errors is derived from a few academic medical center studies, and in general the literature suffers from a lack of standardized research methods, definitions, and systems for monitoring and reporting errors. Their review of this literature does reflect increased risk for those patients who are sicker, over 64 years of age, undergo multiple interventions, remain in a hospital longer, and are treated through an emergency department or in an intensive care unit. The estimates of medical errors outside of the hospital setting is low, with prevalence rates for medical errors in physicians' offices found to be 8% to 9% of all errors.
Methods for monitoring and analyzing medical errors in these studies range from medical chart reviews, adverse drug event records, clinician self-reports, and observational studies. Adverse events are defined differently, allowing underestimation of the error rate. For example, when a mistake is made but caught prior to injury to the patient, how should it be labeled? In many settings these events are termed near misses, rather than mistakes or errors, an event that was recognized and recovered in time to prevent an adverse event. Much less is known about near misses than about true adverse events. In 2000, Weingart et al5 found several additional terms for categorizing medical errors. Some examples are:
Surgical adverse events versus medication errors
Preventable versus unpreventable errors
Diagnostic errors versus therapeutic mishaps
Fatal versus life-threatening versus serious errors
Errors of omission or commission
Clearly any efforts to improve the rates of medical errors are dependent upon a common language for describing and reporting them.4,6
In 2005, researchers with the Joint Commission, previously known as the Joint Commission on Accreditation of Health Organizations (JCAHO), conducted a systematic review of the literature on patient safety terminologies and classifications of errors.7 Their work resulted in a proposal for a standardized patient safety event taxonomy. The goal was to create a multidimensional taxonomy that could be used in various settings and by various practitioners to report incidents of patient safety. The resulting taxonomy includes five primary classification groups, categorizing data that will describe the following aspects of a patient safety event:
The impact schema describes the degree of harm caused to the patient in medical and non-medical contexts. The levels in this taxonomy, shown in Table 3.1, include psychological and physical medical injury, and progress from no harm, to temporary harm at various levels, to permanent harm, to death or profound psychological harm.
Table 3.1Standardized Descriptions of Impact of Patient Safety Events7 Based on the Degree of Resulting Harm ||Download (.pdf) Table 3.1 Standardized Descriptions of Impact of Patient Safety Events7 Based on the Degree of Resulting Harm
|Medical ||Nonmedical |
|Psychological ||Physical ||Legal/Social/Economic |
|No Harm and No Undetectable Harm ||No Harm and No Undetectable Harm || |
|No Detectable Harm ||No Detectable Harm || |
|Temporary ||Permanent ||Temporary ||Permanent || |
|Mild ||Mild ||Mild ||Mild || |
|Moderate ||Moderate ||Moderate ||Moderate || |
|Severe ||Severe ||Severe ||Severe || |
|Profound Mental Harm ||Death || |
The taxonomy for type of error includes three categories:
The inclusion of these three categories illustrates the comprehensive nature of the delivery of patient care and the wide scope of activities in which errors can occur. Communication errors could result from inaccurate and incomplete information, questionable advice or interpretation, questionable consent or disclosure processes, or questionable documentation. Patient management errors can be categorized as emanating from questionable delegation, tracking or follow-up, referral or consultation, or use of resources. The clinical performance errors are grouped into three temporal categories, pre-intervention, intervention, and post-intervention (Table 3.2). Table 3.2 also illustrates the various levels of clinical performance errors, including determining incorrect diagnoses and prognoses.
Table 3.2Standardized Descriptions of Clinical Performance Type of Patient Safety Events ||Download (.pdf) Table 3.2 Standardized Descriptions of Clinical Performance Type of Patient Safety Events
|Pre-intervention A mistake that happens during a history interview, or any time prior to intervention with a patient may be in one of these four categories. ||Intervention A mistake that happens during a patient intervention may be in one of these seven categories. ||Post-intervention A mistake that happens after a patient intervention may be in one of these four categories. |
|Make a correct diagnosis, but choose a questionable intervention ||Correct procedure, with complications ||Correct prognosis |
|Make an inaccurate diagnosis ||Correct procedure, incorrectly performed ||Inaccurate prognosis |
|Make an incomplete diagnosis ||Correct procedure, but untimely ||Incomplete prognosis |
|Make a questionable diagnosis ||Omission of essential procedure ||Questionable prognosis |
| ||Procedure contraindicated || |
| ||Procedure not indicated || |
| ||Wrong patient || |
The domain taxonomy provides a description of the setting of the event, the staff involved, certain patient characteristics, and the targeted type of patient care intervention In this JCAHO taxonomy, descriptions are included that will provide information on patient safety events occurring in several locations in which physical therapists practice, including the rehabilitation component of a hospital, nursing home, rehabilitation facility, and practitioner office. The listing of categories for staff includes physical therapists and occupational therapists. Intervention types include therapeutic, diagnostic, rehabilitation, preventive, or palliative.
The cause taxonomy has two main categories: systems (organization and technical) and human. Systems errors are often not proximate to the patient-clinician relationship but can play a significant role in the context of the safety event. Examples of organizational system causes are the culture—for example, the value for patient safety—or organizational management—for example, the monitoring of unsafe practices. Organizational processes can also affect patient safety, including productivity demands and safety oversight procedures. Technical systems errors typically are found in equipment or materials design, malfunction, or availability. Human errors are categorized as those attributable to the patient, the clinician, or to individuals external to the patient-clinician relationship. Patient errors result from behaviors that are not controllable by the clinician. External human failures are behaviors that are beyond the control of the entire organization. Practitioner errors can be skill-based, rule-based, knowledge-based, or unclassifiable. This classification scheme can be used to identify prevention and mitigation actions that can decrease the rate of medical error by selecting from a variety of procedures that will trigger alerts or alarms for practitioners prior to implementation of services. Techniques are suggested, for example, to improve the accuracy of patient identification, reduce acquired infections, and prevent medication errors.
The authors of the JCAHO patient safety event taxonomy recommend its usage in a wide variety of health care systems, including electronic medical records, to enhance the quality of data on medical errors available to researchers on health care quality and to policy makers. However, they recognize the limitations of such a system to fully capture the nuances of accurately describing medical errors in the following statement:
One source of difficulty we encountered in choosing logical data variables to link disparate terminologies and classifications is that they are all loosely attached in an intricate network of information characterized by events, settings, individuals, and teams of people, protocols, procedures, policies, and communications that function in an uncertain environment.7, p.101
Weingart4 recommends that such a taxonomy will enhance our detection of patterns of medical mistakes; he also acknowledges that "[i]This not obvious, however, that a classification scheme can reliably capture the 'story' of the event and how it unfolded."4, p.93
COGNITIVE ERRORS IN PHYSICIAN DECISION MAKING
Several studies in medicine attempt to focus specifically on the cognitive errors made by physicians as they practice clinical reasoning. Such studies have created categories of cognitive errors by attributing incorrect choices during simulated patient encounters to the patterns of thinking observed in subjects. Young et al8 studied the cognitive processing abilities of 15 residents as they responded to a recall task and two clinical decision scenarios presented as sample cases by a researcher. A variety of cognitive processing errors could be identified, including:
Inaccurate knowledge or incomplete knowledge about some aspect of a complex system, defined as buggy knowledge
Knowledge calibration errors—seen when the residents could not identify gaps in their own knowledge;
Simplifications—using rules of thumb in complex situations;
Attentional dynamics such as situational awareness—the inability to track processes and data in time or across more than one topic
Fixations—inability to reassess a situation in light of new information
Typically, residents with less experience make a greater number of cognitive errors than those with more experience. Studies of cognitive reasoning such as this are often conducted in a laboratory setting, not a clinical setting. (See Chapter 4 for a more detailed discussion of cognitive errors in decision making.)
Studying cognitive processing skills in decision making is one approach to avoiding reasoning errors. Students who struggle with a repeated deficiency in one aspect of knowledge transfer or attentional dynamics may seek help with specifically planned learning experiences to enhance their thinking skills.9 A student or novice clinician might master these cognitive processes in the classroom but have difficulty demonstrating sufficient performance in a busy clinical environment. The guidance of a more experienced clinician can assist the novice to identify errors such as his or her gap in knowledge or the tendency to ignore new exam findings. However, these analytical experiences are often difficult to incorporate into a busy clinician's schedule.
Kempainen et al10 suggest that improvements in clinical reasoning will only happen if physicians have knowledge of cognitive processing and use it to internally monitor their thinking. This requires a commitment of time for reflection on the quality of one's thinking in situations where no known errors have been committed as well as when they have. Borrell-Carrio and Epstein11 have called for physicians to increase self-awareness of their errors in practice through reflection on their abilities to tune or calibrate both their thinking and their emotional responses to the decision confronting them. The habit of self-questioning during clinical work is recommended to increase one's awareness of the personal conditions under which they function during difficult clinical decisions. Mamede et al12 suggest that reflective physicians are those who can examine a decision from a broader perspective and can tolerate or even enjoy the internal tension created when working with complex cases.12 Box 3.1 presents some provocative self-reflective questions drawn from the work of these authors.
ERRORS IN PHYSICAL THERAPY AND OCCUPATIONAL THERAPY PRACTICE
The best description of practice errors has been provided by the medicine, nursing, and pharmacy professions, and most of this work describes medication errors.13 While not as comprehensive, a few authors have reported useful information about the types of errors made by occupational therapists and physical therapists. Scheirton and Mu14,15 have studied errors in occupational therapy practice in physical rehabilitation and geriatric settings, using focus groups and survey research. The majority of practice errors identified by occupational therapists were preventable errors that occurred during patient interventions. Misjudgment and insufficient experience and preparation were identified as potential causes of errors made by the occupational therapists in these studies. These researchers have further investigated the response to errors among these therapists, finding that they reported a significant amount of emotional distress. Coping strategies were used to help the therapist recover from the effects of the error, including: a corrective action plan for the therapist, volunteering to spend extra time with the injured patient, and making constructive practice changes to prevent a similar error in the future. These authors have included physical therapists in some of their focus group research on patient safety and reported an ethical analysis of six cases of error committed by physical and occupational therapists in a recent report.16 They identified that the cases illustrated what they termed technical and moral errors; analysis of moral errors focused on the ethical responsibilities of the clinicians in each case.
Box 3.1 Questions to Enhance Self-awareness of errors in Clinical Reasoning
How open am I to my patient's view of his/her symptoms?
How motivated am I to solve this problem?
Do I have sufficient energy or focus at this time to make the best decision?
What factors in the patient's response to me are influencing my thinking; for example, is the patient hostile or desperate?
Did I close the alternative options for this patient too soon?
Is any previous negative outcome with a similar patient affecting my decision making abilities?
What am I assuming about this patient that may not be true?
Am I being judgmental about this patient in a negative or positive way?
What is my frustration level, and how is it influencing my thinking?
What surprised me about this patient?
Much less research has been conducted on the types of errors that characterize physical therapist practice. In 1992, Deusinger17 reported the results of telephone interviews with 119 physical therapists in Missouri who agreed to discuss clinical errors in their practice careers. The author attempted to develop a typology to categorize the reported errors as to:
Type—defined as an error of omission or commission
Action—defined as decision making, interpersonal communications, technical or psychomotor skills, or cognitive factors related to knowledge
Consequences—defined as potential versus actual, and as social or physical
The typology demonstrated reliability only in categorizing the error type and the consequences. Sixty-one different tasks were described by the subjects as associated with errors in practice, 13 of which accounted for 65% of the errors. The majority of errors occurred during intervention tasks (29%) such as gait, modalities, and exercise. Eighteen percent of the errors were attributed to mistakes in planning the patient's program or delegation of care. Only 7% of errors were reported during the action of examination or evaluation, perhaps attributable to the time frame of data collection (1986). Subjects were asked to report the likely cause of the error, and these data appear to reflect findings similar to those in medicine, with the most frequent causes reported including inadequate knowledge or clinical experience and cognitive failures including inaccurate assumptions and failure to consider consequences of the decision. Environmental factors were also identified, including time pressures and inadequate staffing or supervision.
Errors and Error Prevention Across Patient/Client Care Management Model
As seen in the research efforts in medicine, the types of errors and the consequences of these errors should be of specific interest to physical therapists who wish to improve their clinical expertise. One perspective for studying the type of errors physical therapists make is to consider the management model developed by the APTA,18 discussed in Chapter 1. Using this model to evaluate errors in practice may focus attention on the elements of patient management activities that place patients at the most risk. This perspective may also be helpful for analyzing cognitive errors or problems with thinking, as the patient management model represents actions performed with the patient in a temporal fashion. For example, what are the consequences for clinical decisions about interventions, if diagnosis is incorrect?
The physical therapist patient management model begins with clinical decisions about how to examine the patient. The therapist must conduct an appropriate history interview, select which systems to screen and examine, and then select the correct tests and measures to perform with the patient. Each test must be performed accurately and interpreted correctly to inform the evaluation of the patient's condition. This is not only the first interaction between patient and therapist but, some would say, the most important element of the model in which to strive for clinical expertise. Groopman19 suggests many cognitive errors that happen during the medical interview derive from poor physician communication skills. A few of these include failing to actively listen to the patient, ask open-ended questions in a manner that communicates interest in the patient, and follow up on aspects of the patient's story. Roter et al20,21 found that physician's use of good communication skills can enhance the patient's involvement in problem posing and problem solving collaborations during the interview. In Section Two Coulehan and Block discuss ways to improve the interview process to overcome these types of errors and Gordon, Nixon-Cave, and Johnson all provide information about exploring patients' values as a component of the therapeutic alliance.
Tests and Measures As clinicians with over 800 physical performance tests and measures at our disposal, physical therapists face a challenge in selecting a test with the best diagnostic properties for each patient problem reported. Evidence regarding the diagnostic accuracy of many of these tests has increased significantly over the past decade.22,23,24,25 Physical therapists who increase their knowledge of these studies, especially for the most frequently used tests in their practice, will enhance their ability to avoid the errors of selecting inappropriate tests, in applying and interpreting the tests, and in over- or underutilization of tests. The consequences of errors in decision making during the examination phase include overtesting that can cause increased pain to the patient, undertesting that can cause the physical therapist to make an incorrect diagnosis, and poor communication that can create an adversarial patient-therapist relationship.
Once the examination data have been collected, the physical therapist evaluates the data to determine the patient's diagnosis. These data will be used in developing a prognosis and a plan of care. Diagnostic errors may result in incorrect or incomplete diagnoses, such as when one aspect of the diagnosis is missed completely. How might these errors occur? Perhaps the physical therapist misinterprets the data from the examination due to not being able to conduct the test accurately; for example, a test appears to produce normal results but the clinician may not have had sufficient strength to administer the test on a particularly large patient. Other sources of cognitive diagnostic errors include incorrectly identifying a pathological structure or movement pattern or miscategorizing the nature of the patient's movement impairments. Diagnostic errors also might be a result of cognitive, communication, or technical errors occurring during the examination phase of patient management. Thus an error occurring earlier in the patient management process will likely influence the next phase of decision making. For novices, diagnostic errors may occur due to the inability to put all the examination data together into a cogent hypothesis that fits.26
The ability to see patterns emerging from examination data is developed through reflective practice by expert physical therapists.27 Experts are skilled evaluators, as they combine their content knowledge, their knowledge of the patient and of self, and their practice knowledge to make diagnostic decisions. The consequences of a misdiagnosis in physical therapy are not precisely known, but may include inappropriate selection of interventions that may cause injury to the patient or extend the time needed to reach a successful conclusion of care, delayed referral of the patient to an appropriate practitioner for further diagnostic evaluation, or labeling and treating patients unnecessarily when misidentifying their movement patterns as abnormal.
Prognostic errors occur in practice when the physical therapist does not accurately predict the natural course or progress of the patient's pathology or impairments, or the recovery of functional performance, or future disability level. Perhaps a client might be advised to return to work or sports activity at too early a point in his or her recovery. Prognostic errors might also result in either over- or underutilization of health care resources of all types, including durable medical equipment or disposition placement for continuing care. Avoiding prognostic errors is difficult for physical therapists because our health care system partitions the continuous care of our patient among more than one physical therapist, passing the patient along to the physical therapist practicing in the acute care setting, the home health setting, or the outpatient setting. These disconnected care patterns make it difficult for the physical therapists to gain information on patient outcomes that can inform their decisions during their interactions with the patient. Physical therapists must work to discover methods to monitor the long-term outcomes of their patients in order to build the experiential knowledge base that will enhance future prognostic decisions.
Errors that occur during physical therapist interventions are perhaps the most obvious clinical practice mistakes because they may risk the physical safety of the patient. In addition to the psychomotor skills required of many clinical interventions, the physical therapist must know which intervention to choose, when and where to apply them, and with what force. Any misjudgment of one of these aspects of the intervention can change the right treatment into a dangerous treatment rather quickly. An accessible store of knowledge of past patients' reactions to interventions, coupled with close monitoring of the patient during treatment, may reduce the occurrence of intervention errors in clinical practice.
Errors that may accompany the outcomes of physical therapy care can best be described as a mismatch between the outcome measures selected by the physical therapist and the patient's goals or circumstances. The physical therapist may believe the care delivered was successful based upon an improvement in the patient's pain scores, but the patient may have functional goals that were never identified or addressed. The assumption that a patient's function will automatically return once pain is reduced can represent an error of faulty logic on the therapist's part. If the therapist does not fully consider the patient's circumstances, this may also lead to a mismatch in treatment outcomes. For example, the therapist may underestimate the aerobic or muscular endurance required for mobility by a patient living in a very rural environment.
Implications of errors in Physical Therapy Practice
We are just beginning to understand the importance of learning about practice errors in the physical therapy profession. It can be a difficult topic to discuss, as physical therapists cannot avoid their natural human tendency to deny fault, blame others including the patient, and refuse to acknowledge that an error has been made, whether or not injury to the patient has occurred. Ethicist Ruth Purtillo28 reminds us that despite the best training physical therapists are not immune to situations where harm occurs. She then challenges the profession and individual clinicians to confront tendencies to deny the errors we make, to acknowledge them to ourselves and to the affected patient, and further to offer an apology and request forgiveness. Only when these steps in response to an error are taken, suggests Purtilo, can the therapeutic relationship between patient and therapist be restored.
The benefits of studying errors in clinical practice are significant for both clinicians and the profession. Knowing more about the effects of errors or near misses in physical therapy can enhance our understanding of practice in ways we do not often pursue. For example, if a clinician gives a patient a diagnosis of a labral tear at the shoulder, without the assistance of diagnostic imaging, and treats her conservatively for instability, pain, and decreased function, but the patient actually has a bicepital tendonosis, will the error in diagnosis make any difference in the short- and long-term outcomes for this patient? Likely not, as the conservative treatment approach for both of these pathologies is similar. How precise are our diagnostic categories in physical therapy, and how precise do they need to be, given the interventional options? To move our science and practice to a higher level, we can study our diagnostic errors and identify which diagnostic mistakes carry the most risk for our patients. In some diagnostic groups, it is the missed diagnosis that presents the most risk, for example, failing to refer a patient with a suspicious skin lesion for further testing. In some diagnostic groups, it is the misdiagnosis that places the patient at risk, for example, diagnosing an ankle sprain versus a fracture of the talus.
Occasionally a clinician will conclude a course of physical therapy with a patient, fighting a nagging concern that neither the patient's diagnosis nor the intervention was quite right, and that the patient got better anyway. This might be referred to as a good outcome that is robust to both diagnostic and interventional errors. It also might be considered inappropriate treatment of a pathology that has a natural history of improvement without care. Or the good outcome might be the result of the placebo effect that results from the attention and care of the physical therapist and has little to do with the direct effects of the interventions chosen. Our practice would be enhanced if we knew which of the explanations was accurate.
Placebo: really there or just imagination? The term placebo often causes much confusion. We often first think of "placebo" as the label used to describe a sham treatment in an experiment that studies the efficacy of an intervention. In this context it often connotes "nothing," as in one group receiving ultrasound and exercise and the other group receiving a "placebo." But the placebo effect is quite different. It has been described as the measurable positive response to an inert intervention; therefore the responses are thought to be due to factors related to the patient's belief in the positive outcomes of the intervention. In contrast, the nocebo effect is described as the measurable negative response to inert interventions that patients believe will have negative effects. More recently, authors of a systematic review of over 200 articles on the placebo effect concluded that there is little evidence of a true placebo effect in observer-reported outcomes but that there may be in patient-reported outcomes, particularly pain.29 The concept of the placebo effect remains a matter of some interest in physical therapy, since so much of our care is directed toward improving patient-reported outcomes.
DECISION MAKING UNDER UNCERTAINTY
Many of the errors that we have discussed can find their basis in the uncertainty that surrounds the data we use to make decisions. Those who write about decision making under uncertainty advocate improving our knowledge by learning more about a few key variables.
Expected Value of Alternatives
One variable is the expected value of alternatives. For example, knowing whether a patient prefers more normality by learning ambulation after a serious stroke or faster functionality by using an electric wheelchair can help us decide more accurately what our course of intervention should be. Also, knowing the level of risk aversion or risk seeking our patients and we are comfortable with can also reduce errors. It is especially important to know if there is a disparity between our patient's preferences and our own.30 As stated by an expert pediatric physical therapist, "I think one of the things I have learned over the past couple of years… is that the parents' goals are the goals, and the child's goals are the goals. It's not that the therapist's goals are the goals."27
But perhaps the most important variable we must understand to reduce error is the concept of probability, along with the actual probabilities associated with the options in each clinical decision. The concept of probability helps us recognize that our decisions are not based on certainty. This by itself improves decision making. And identifying specific probabilities improves it even more.
There are a few pieces of data that help us understand probability. For example, we first need to know the base rate of the event with which we are concerned: just how many people have this problem? Base rate is measured by both the prevalence (how many people have this problem now) and incidence of the problem (how many people get this problem in any given time period).
Without knowing the base rate, a comment such as "people in a particular group who received a particular drug are twice as likely (100% increase) to commit suicide" means almost nothing. We need to know just how many people in the group commit suicide without the drug. If the suicide rate is 10,000 per 1,000,000 (1%), then a 100% increase means 20,000 per 1,000,000. This might be a very acceptable increase if the drug provides relief from serious symptoms in the remaining 980,000 people. But if the suicide rate is 250,000 per 1,000,000 (25%), then a 100% increase means 500,000 per 1,000,000. That much mortality may be unacceptable!
In addition to base rate, we also need to know the likelihood that an intervention will lead to either an improvement or decrement in the patient's status. These measures include things such as absolute and relative risk. These types of data and the statistics that analyze them are discussed in the epidemiology literature.31,32 We discuss more detailed ways to understand the research on specific probabilities in Chapter 12. Chapter 4 contains many examples of the faults in decision making that we can all experience. Understanding the concept of probability and knowing actual probabilities can assist us in avoiding these faults.
We all make mistakes! As we have discussed in this chapter, there are many sources for the mistakes that we make.
First, we know that biologically based events are inherently probabilistic; almost nothing about illness and disease can be known with absolute certainty. The best way to deal with this source of error is to understand what is known about probabilities and take that into account in decision making.
Second, the level of knowledge about the topic may not be currently sufficient; science may not yet have discovered the information necessary to understand what is happening. The only way to deal with this source of error is to remain vigilant about new knowledge as it appears.
Third, knowledge might exist about the topic but we, personally, have not yet learned it. Again, vigilance about identifying knowledge new to us is essential.
Fourth, we know what the best option for the patient's problem is but choose not to take that option because it is not in our best interest; we violate the patient's trust in us. The remedy for this source of error is to always make the ethical choice.
Fifth, we do not think in a logical way about the information we have available to us. A remedy for this is to understand the errors we humans typically make in our logic.
The first two causes are beyond our control, as we cannot change the nature of biological events, nor can we know something not yet known. But we can work to reduce the impact of the latter three causes of errors. Section Three of this book provides many tools to overcome deficiencies in our own knowledge. Section Two provides ways to reflect on actions to overcome the temptation to violate the patient's trust. The remaining chapters in Section I identify ways to improve our logic in our patient care–related decision making.
Think about a mistake that you have made in patient care. Apply the categories from the JCAHO taxonomy and then determine if this can lead you to identify ways to prevent similar mistakes in the future.
Use the questions listed in Box 3.1 to reflect on the characteristics of your own thought processes as you approach patient care.
Identify a specific patient whom you have treated lately and follow the patient across the patient/client management model. At each phase identify a potential error and then determine what the results of that error would have been.
Choose one of the many nonfiction books written about medical errors. After reading it, and after reading this section of the book, reflect on what can reasonably be learned from these books. Do they simply tell scary or interesting stories, or do they teach lessons that can be applied to your patients? The list below is just a small sample of these books.
Banja J, Medical Errors and Medical Narcissism
Geller ES, Johnson D, The Anatomy of Medical Error: Preventing Harm with People-Based Patient Safety
Groopman J, How Doctors Think
Nuland S, The Soul of Medicine
R. Evidence-based Medicine: How to Practice It and Teach It, 4th ed. Edinburgh: Churchill Livingstone; 2011.
LI. Looking for medical injuries where the light is bright. JAMA. Oct 8 2003;290(14):1917–1919.
M, eds. To Err is Human: Building a Safer Health System. Washington, DC: National Academy Press; 1999.
SN. Beyond Babel: prospects for a universal patient safety taxonomy. Int J Qual Health Care. Apr 2005;17(2):93–94.
B. Epidemiology of medical error. BMJ. Mar 18 2000;320(7237):774–777.
DM. Five years after To Err Is Human
: What have we learned? JAMA. May 18 2005;293(19):2384–2390.
JM. The JCAHO patient safety event taxonomy: A standardized terminology and classification schema for near misses and adverse events. Int J Qual Health Care. Apr 2005;17(2):95–105.
B. How residents think and make medical decisions: Implications for education and patient safety. Am Surg. Jun 2007;73(6):548–553; discussion 553–544.
A. Clinical problem solving and diagnostic decision making: Selective review of the cognitive literature. BMJ. Mar 23 2002;324(7339):729–732.
FM. Understanding our mistakes: A primer on errors in clinical reasoning. Med Teach. Mar 2003;25(2):177–181.
RM. Preventing errors in clinical practice: A call for self-awareness. Ann Fam Med. Jul–Aug 2004;2(4):310–316.
R. Diagnostic errors and reflective practice in medicine. J Eval Clin Pract. Feb 2007;13(1):138–145.
DW. Medication errors: Not just a few "bad apples". J Clin Outcomes Manag. Feb 2006;13(2):114–115.
L. Occupational therapy practice errors in physical rehabilitation and geriatrics settings: A national survey study. Am J Occup Ther. May–Jun 2006;60(3):288–297.
H. Occupational therapists' responses to practice errors in physical rehabilitation settings. Am J Occup Ther. May–Jun 2003;57(3):307–314.
TM. Error and patient safety: Ethical analysis of cases in occupational and physical therapy practice. Med Health Care Philos. Sep 2007;10(3):301–311.
S. Analyzing errors in practice: A vehicle for assessing and enhancing the quality of care. Int J Technol Assess Health Care. 1992;8(1):65–78.
American Physical Therapy Association. Guide to Physical Therapist Practice, 2nd ed. Alexandria, VA: APTA; 2002.
J. How Doctors Think. Boston: Houghton Mifflin Company; 2007.
D. The medical visit context of treatment decision-making and the therapeutic relationship. Health Expect. Mar 2000;3(1):17–25.
JA. Physician gender and patient-centered communication: A critical review of empirical research. Annu Rev Public Health. 2004;25:497–519.
I, Ebrahim Mousavi
M. Sensitivity, specificity and predictive value of the clinical trunk muscle endurance tests in low back pain. Clin Rehabil. Jul 2007;21(7):640–647.
E. Orthopedic Physical Examination Tests: An Evidence Based Approach. Upper Saddle River, NJ: Prentice Hall; 2007.
et al. Interrater reliability and diagnostic accuracy of pelvic girdle pain classification. J Manipulative Physiol Ther. May 2007;30(4):252–258.
LA. Reliability and diagnostic accuracy of history and physical examination for diagnosing glenoid labral tears. Am J Sports Med. Jan 2008;36(1):162–168.
L. The novice versus the experienced clinician: Insights into the work of the physical therapist. Phys Ther. 1990;70:314–323.
KF. Expertise in Physical Therapy Practice, 2nd ed. St. Louis, MO: Elsevier; 2007.
RB. Beyond disclosure: Seeking forgiveness. Phys Ther. Nov 2005;85(11):1124–1126.
PC (20 January 2010). Placebo interventions for all clinical conditions. Cochrane Database Syst Rev 106 (1): CD003974.
MH. Judgment in Managerial Decision Making, 5th ed. John Wiley & Sons; 2002.
DL. Biostatistics: The Bare Essentials, 3rd ed. Shelton, CT: People's Medical Publishing House; 2008.
P. Clinical Epidemiology: How to Do Clinical Practice Research, 3rd ed. Philadelphia: Lippincott Williams and Wilkins; 2005.