Malpractice Concerns, Defensive Medicine, and the Histopathology Diagnosis of Melanocytic Skin Lesions

Linda J. Titus, PhD; Lisa M. Reisch, PhD; Anna N. A. Tosteson, ScD; Heidi D. Nelson, MD, MPH; Paul D. Frederick, MPH, MBA; Patricia A. Carney, PhD; Raymond L. Barnhill, MD, MSc; David E. Elder, MBChB, FRCPA; Martin A. Weinstock, MD, PhD; Michael W. Piepkorn, MD, PhD; Joann G. Elmore, MD, MPH

Disclosures

Am J Clin Pathol. 2018;150(4):338-345.

Abstract and Introduction

Abstract

Objectives: The impact of malpractice concerns on pathologists' use of defensive medicine and interpretations of melanocytic skin lesions (MSLs) is unknown.

Methods: A total of 207 pathologists interpreting MSLs responded to a survey about past involvement in malpractice litigation, influence of malpractice concerns on diagnosis, and use of assurance behaviors (defensive medicine) to alleviate malpractice concerns. Assurance behaviors included requesting second opinions, additional slides, additional sampling, and ordering specialized tests.

Results: Of the pathologists, 27.5% reported that malpractice concerns influenced them toward a more severe MSL diagnosis. Nearly all (95.2%) pathologists reported practicing at least one assurance behavior due to malpractice concerns, and this practice was associated with being influenced toward a more severe MSL diagnosis (odds ratio, 2.72; 95% confidence interval, 1.41–5.26).

Conclusions: One of four US skin pathologists upgrade MSL diagnosis due to malpractice concerns, and nearly all practice assurance behaviors. Assurance behaviors are associated with rendering a more severe MSL diagnosis.

Introduction

The incidence of melanoma in US whites has risen steadily over the past few decades.^[1] The American Cancer Society estimated 91,270 new cases of melanoma will be diagnosed in the United States in 2018, and 9,320 individuals will die of the disease.^[2]

At present, complete surgical removal of an early melanoma offers the best chance of curing this disease, underscoring the importance of timely removal and an accurate histopathology diagnosis. Unfortunately, the pathologic interpretation of melanoma is difficult, particularly for melanoma in situ and early invasive melanoma.^[3,4] Given these challenges, it is not surprising that a missed diagnosis of melanoma has been cited as the most common cause of medical malpractice claims against a pathologist.^[5] Dermatopathologists rank second highest among all medical specialties for the number of malpractice verdicts exceeding $1,000,000.^[6] The risk of malpractice for those who interpret melanocytic lesions has been attributed to a variety of factors, including lesion complexity and the difficulty of distinguishing between benign and invasive melanocytic lesions with currently available histopathologic criteria, even among highly skilled dermatopathologists.^[3,7]

To allay concerns about medical malpractice litigation, many physicians practice defensive medicine. Defensive medicine includes the use of assurance behaviors (eg, ordering additional tests, requesting second opinions) that are intended to reduce exposure to malpractice litigation but may not clinically benefit the patient.^[8] The use of assurance behaviors is thought to be widespread in the United States and appears to be increasing.^[9] National surveys indicate that 88% to 91% of physicians practice defensive medicine or assurance behaviors to reduce their risk of malpractice litigation.^[10–12] In addition, in a recent survey, 41% of medical students and 53% of medical residents reported being taught assurance behaviors by an attending physician.^[13]

We previously reported that a third of participating pathologists who regularly interpret melanocytic skin lesions (MSLs) had past experience with malpractice litigation and that this experience was not associated with the use of assurance behaviors.^[14] The present report expands our past investigation in two important areas. First, we examine whether pathologists' concerns about medical malpractice influence the direction of their diagnosis when interpreting MSLs and, specifically, whether medical malpractice concerns result in upgrading an MSL diagnosis. Second, we evaluate an array of pathologist characteristics, including past malpractice experience and the use of assurance behaviors in relation to the influence of malpractice concerns on the direction of MSL diagnosis.

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Table 1. Unadjusted ORs and 95% CIs for the Associations Between Pathologist Demographics, Training, and Clinical Experience and Influence Toward a More Severe MSL Diagnosis Due to Concerns About Medical Malpractice (n = 207) ^a
Pathologist Characteristic	All Pathologists, No. (%)	Influence Toward a More Severe Diagnosis, No. (%)	No Influence on Diagnosis, No. (%)	OR (95% CI)^b	P Value
Total	207 (100.0)	57 (27.5)	150 (72.5)
Demographics
Age, y					.007
<50	95 (45.9)	35 (36.8)	60 (63.2)	Reference
≥50	112 (54.1)	22 (19.6)	90 (80.4)	0.42 (0.23–0.79)
Sex					.13
Male	123 (59.4)	29 (23.6)	94 (76.4)	Reference
Female	84 (40.6)	28 (33.3)	56 (66.7)	1.62 (0.87–2.99)
Training and clinical experience
Residency training					.10
Anatomic/clinical pathology	186 (89.9)	48 (25.8)	138 (74.2)	Reference
Dermatology	21 (10.1)	9 (42.9)	12 (57.1)	2.17 (0.86–5.47)
Fellowship training/board certification					.81
Other^c	126 (60.9)	34 (27.0)	92 (73.0)	Reference
Dermatopathology^d	81 (39.1)	23 (28.4)	58 (71.6)	1.08 (0.58–2.00)
Years interpreting MSLs					<.001
<20	143 (69.1)	50 (35.0)	93 (65.0)	Reference
≥20	64 (30.9)	7 (10.9)	57 (89.1)	0.24 (0.10–0.56)
MSL volume^e					.32
<35	76 (36.7)	24 (31.6)	52 (68.4)	Reference
≥35	131 (63.3)	33 (25.2)	98 (74.8)	0.73 (0.39–1.36)
Total number of MSLs (per month)^e
Mean (SD)	125 (178.0)	111 (131.5)	131 (192.9)	1.00 (0.99–1.01)^f	.58
For what percentage of MSLs is your final assessment that the diagnosis is borderline or uncertain?					.28
None	21 (10.1)	3 (14.3)	18 (85.7)	Reference
1%-4%	93 (44.9)	24 (25.8)	69 (74.2)	1.86 (0.53–6.55)
≥5%	93 (44.9)	30 (32.3)	63 (67.7)	2.54 (0.73–8.84)
Have you ever been named in a medical malpractice suit					.70
Never been sued	139 (67.1)	41 (29.5)	98 (70.5)	Reference
Yes, related to MSL	12 (5.8)	3 (25.0)	9 (75.0)	0.87 (0.23–3.30)
Yes, not related to MSL	56 (27.1)	13 (23.2)	43 (76.8)	0.74 (0.36–1.51)

CI, confidence interval; MSL, melanocytic skin lesion; OR, odds ratio; SD, standard deviation.
^aPercentages may not total 100 due to rounding.
^bFirth's bias reduction method based on penalized likelihood (addresses issues of separability, small sample sizes, and bias of the parameter estimates). Wald χ² statistics were used to test the effect each independent coefficient had on the direction of influence.
^cIncludes fellowships or board certifications in surgical pathology, cytopathology, or hematopathology.
^dPathologists in this category have single or multiple certifications/fellowship training, including dermatopathology.
^eSum of number of melanomas + benign MSLs interpreted per month.
^fOdds ratio for every 5-unit increment in number of MSLs per month.

Table 2. Unadjusted ORs and 95% CIs for the Associations Between Pathologist Perceptions and Influence Toward a More Severe MSL Diagnosis Due to Concerns About Medical Malpractice (n = 207) ^a
Perceptions: What Are Your Thoughts on Interpreting MSLs?^b	All Pathologists, No. (%)	Influence Toward a More Severe Diagnosis, No. (%)	No Influence on Diagnosis, No. (%)	OR (95% CI)^c	P Value
Total	207 (100.0)	57 (27.5)	150 (72.5)
Interpreting melanocytic skin lesions is enjoyable					.56
No	63 (30.4)	19 (30.2)	44 (69.8)	Reference
Yes	144 (69.6)	38 (26.4)	106 (73.6)	0.83 (0.43–1.58)
In general, melanocytic skin lesions are challenging to interpret					.48
No	8 (3.9)	1 (12.5)	7 (87.5)	Reference
Yes	199 (96.1)	56 (28.1)	143 (71.9)	1.97 (0.30–12.96)
Interpreting melanocytic skin lesions makes me more nervous than other types of pathology					.058
No	61 (29.5)	11 (18.0)	50 (82.0)	Reference
Yes	146 (70.5)	46 (31.5)	100 (68.5)	2.03 (0.98–4.23)
I am concerned about patient safety and potential harm to patients that may result from my assessment of melanocytic skin lesions					.07
No	52 (25.1)	9 (17.3)	43 (82.7)	Reference
Yes	155 (74.9)	48 (31.0)	107 (69.0)	2.07 (0.94–4.53)
In general, too many melanocytic skin lesions are being biopsied					.066
No	123 (59.4)	28 (22.8)	95 (77.2)	Reference
Yes	84 (40.6)	29 (34.5)	55 (65.5)	1.78 (0.96–3.29)
In general, pathologists are overcalling some benign lesions as melanoma					>.99
No	98 (47.3)	27 (27.6)	71 (72.4)	Reference
Yes	109 (52.7)	30 (27.5)	79 (72.5)	1.00 (0.54–1.83)
In general, I am confident in my assessments of melanocytic skin lesions^d					.94
No	29 (14.0)	8 (27.6)	21 (72.4)	Reference
Yes	178 (86.0)	49 (27.5)	129 (72.5)	0.97 (0.40–2.31)
Requesting second opinions protects me from malpractice suits					.43
No	29 (14.0)	6 (20.7)	23 (79.3)	Reference
Yes	178 (86.0)	51 (28.7)	127 (71.3)	1.46 (0.57–3.74)

CI, confidence interval; MSL, melanocytic skin lesion; OR, odds ratio.
^aPercentages may not total 100 due to rounding.
^b"No" is defined by Likert scale responses disagree (slightly disagree, disagree, strongly disagree) and "yes" is defined by agree (slightly agree, agree, strongly agree). Pathologists reported how challenging they found melanocytic skin lesions to interpret based on a 6-point Likert scale ranging from 1 ("very easy") to 6 ("very challenging"). When pathologists were asked if they felt melanocytic skin lesions were challenging to interpret, a "No" response is defined by Likert scale responses 1, 2, 3 and "Yes" is defined by Likert scale responses 4, 5, 6. Pathologists also reported how confident they were in their assessments of melanocytic skin lesions based on a 6-point Likert scale ranging from 1 ("very confident") to 6 ("not at all confident"). When pathologists were asked if they were confident in their assessments of melanocytic skin lesions, a "No" response is defined by Likert scale responses 4, 5, 6 and "Yes" is defined by Likert scale responses 1, 2, 3. For all other responses, "No" is defined by Likert scale responses disagree (slightly disagree, disagree, strongly disagree) and "Yes" is defined by agree (slightly agree, agree, strongly agree).
^cFirth's bias reduction method based on penalized likelihood (addresses issues of separability, small sample sizes, and bias of the parameter estimates). Wald χ² statistics were used to test the effect each independent coefficient had on the direction of influence.
^dReference reversed to be consistent with questions in which disagree is the reference for a positive response.

Table 3. Unadjusted ORs and 95% CIs for the Associations Between Pathologist Practice of Assurance Behaviors and Influence Toward a More Severe MSL Diagnosis Due to Concerns About Medical Malpractice (n = 207) ^a
How Do Medical Malpractice Concerns Affect Your Own Practice When Interpreting MSLs?	All Pathologists, No. (%)	Influence Toward a More Severe Diagnosis, No. (%)	No Influence on Diagnosis, No. (%)	OR (95% CI)^b	P Value
Total	207 (100.0)	57 (27.5)	150 (72.5)
1. I request additional slides cut from the block					.017
No	27 (13.0)	1 (3.7)	26 (96.3)	Reference
Yes	180 (87.0)	56 (31.1)	124 (68.9)	8.02 (1.46–44.11)
2. I recommend additional surgical sampling					.047
No	70 (33.8)	13 (18.6)	57 (81.4)	Reference
Yes	137 (66.2)	44 (32.1)	93 (67.9)	2.03 (1.01–4.07)
3. I request second opinions					.10
No	16 (7.7)	1 (6.3)	15 (93.8)	Reference
Yes	191 (92.3)	56 (29.3)	135 (70.7)	4.31 (0.74–24.92)
4. I order additional tests such as IHC and or molecular tests					.16
No	78 (37.7)	17 (21.8)	61 (78.2)	Reference
Yes	129 (62.3)	40 (31.0)	89 (69.0)	1.59 (0.83–3.05)
Composite variable for assurance behaviors
Practiced at least one of four assurance behaviors (strongly agree vs all other responses)					.002
No (disagree/slightly disagree, agree/slightly agree)	131 (63.3)	26 (19.8)	105 (80.2)	Reference
Yes (strongly agree)	76 (36.7)	31 (40.8)	45 (59.2)	2.76 (1.47–5.15)

CI, confidence interval; IHC, immunohistochemistry; MSL, melanocytic skin lesion; OR, odds ratio.
^aPercentages may not total 100 due to rounding. Except where noted, "no" is defined by Likert scale responses disagree (slightly disagree, disagree, strongly disagree) and "yes" is defined by agree (slightly agree, agree, strongly agree).
^bFirth's bias reduction method based on penalized likelihood (addresses issues of separability, small sample sizes, and bias of the parameter estimates). Wald χ² statistics were used to test the effect each independent coefficient had on the direction of influence.

Table 4. Adjusted ORs and 95% CIs for the Associations Between Pathologist Characteristics and Influence Toward a More Severe MSL Diagnosis Due to Concerns About Medical Malpractice ^a
Pathologist Characteristic	OR (95% CI)	P Value
Residency training
Anatomic/clinical pathology	Reference
Dermatology	1.65 (0.61–4.43)	.32
Years interpreting MSL
<20	Reference
≥20	0.29 (0.12–0.69)	.005
I am concerned about patient safety and potential harm to patients that may result from my assessment of melanocytic skin lesions
Disagree	Reference
Agree	1.74 (0.76–3.98)	.19
In general, too many melanocytic skin lesions are being biopsied
Disagree	Reference
Agree	1.58 (0.81–3.08)	.18
Composite assurance variable^b
None	Reference
Strongly agrees with practicing at least one of four assurance behaviors	2.72 (1.41–5.26)	.003

CI, confidence interval; MSL, melanocytic skin lesion; OR, odds ratio.
^aResults based on a multivariable logistic regression model containing the terms shown in the model. Variables chosen for multivariable modeling were those associated with influence toward a more severe diagnosis at P ≤ .10 in simple logistic models. The OR for each variable is adjusted for all other terms in the table.
^bAssurance behaviors include requesting additional slides from the block, recommending additional surgical sampling, requesting second opinions, and ordering additional tests such as immunohistochemistty and other molecular tests.