Respondents
189 of 624 (30.3%) physicians completed the survey with an additional 65 of 624 (10%) partial responses. 7 of 189 (4%) respondents were excluded for answering the vignette in less than 5 seconds or more than 500 seconds. There was even randomization into the control (10%, n=64), TC (9%, n=56), and COL (10%, n=62) groups. Partial responses (P=0.26) or exclusions (P=0.28) were similar between groups (Figure 2). Physician demographic dispersions were reflective of the population at both institutions; most were 31 to 40 years old (49%, n=89) and male (59%, n=108). Most were also attending physicians (54%, n=98), general internists/hospitalists (53%, n=97), and had relatively infrequent experience managing patients with septic shock in the last 90 days (0 to 10 patients, 54%, n=99) and 365 days (0 to 25 patients, 42%, n=77). However, 167 of 189 (88.5%) physicians accurately identified the 2016 SSC initial fluid resuscitation guidelines. There were no significant differences between intervention groups (Table 1).
Table 1. Respondent Demographic Characteristics by Intervention Group
|
Control
(n=64)
|
Time Constraint (n=56)
|
Choice Overload (n=62)
|
All
(n=184)
|
P Value‡
|
Age, No. (%)
|
|
|
|
|
|
21-30 years old
|
22 (34.4)
|
11 (19.6)
|
16 (25.8)
|
49 (26.9)
|
0.64
|
31-40 years old
|
26 (40.6)
|
33 (58.9)
|
30 (48.4)
|
89 (48.9)
|
41-50 years old
|
13 (20.3)
|
8 (14.3)
|
11 (17.7)
|
32 (17.6)
|
51-60 years old
|
1 (1.6)
|
2 (3.57)
|
5 (8.1)
|
8 (4.4)
|
> 60 years old
|
2 (3.1)
|
3 (3.57)
|
0 (0)
|
4 (2.2)
|
Gender, No. (%)
|
|
|
|
|
|
Female
|
28 (43.8)
|
21 (37.5)
|
23 (37.1)
|
72 (39.6)
|
0.70
|
Male
|
36 (56.3)
|
35 (62.5)
|
37 (59.68)
|
108 (59.3)
|
Transgender Male
|
0 (0)
|
0 (0)
|
1 (1.6)
|
1 (0.6)
|
Gender Variant/Non-Conforming
|
0 (0)
|
0 (0)
|
1 (1.6)
|
1 (0.6)
|
Race, No. (%)
|
|
|
|
|
|
White
|
56 (83.4)
|
48 (85.7)
|
54 (87.1)
|
158 (85.9)
|
0.96
|
Hispanic or Latino
|
3 (4.7)
|
0 (0)
|
0 (0)
|
3 (1.6)
|
Black or African American
|
1 (1.6)
|
0 (0)
|
1 (0)
|
2 (0.5)
|
American Indian or Alaska Native
|
0 (0)
|
0 (0)
|
0 (0)
|
0 (0)
|
Asian
|
4 (6.3)
|
7 (12.5)
|
6 (9.7)
|
17 (9.2)
|
Native Hawaiian or Pacific Islander
|
0 (0)
|
1 (1.8)
|
0 (0)
|
1 (0.5)
|
Multiracial
|
1 (1.6)
|
0 (0)
|
1 (1.6)
|
2 (1.1)
|
Prefer not to answer
|
1 (1.6)
|
0 (0)
|
1 (1.6)
|
2 (1.1)
|
Training, No. (%)
|
|
|
|
|
|
Intern/Resident PGY1
|
6 (9.4)
|
6 (10.7)
|
4 (6.5)
|
16 (8.8)
|
0.99
|
Resident PGY2
|
7 (10.9)
|
4 (7.1)
|
8 (12.9)
|
19 (10.4)
|
Resident PGY3
|
8 (12.5)
|
6 (10.7)
|
7 (11.3)
|
21 (11.5)
|
Resident PGY4 or above
|
3 (4.7)
|
2 (3.6)
|
1 (1.6)
|
6 (3.3)
|
Fellow
|
5 (7.8)
|
8 (14.3)
|
9 (14.5)
|
22 (12.1)
|
Attending/Staff
|
35 (54.7)
|
30 (53.6)
|
33 (52.2)
|
98 (53.9)
|
Specialty, No. (%)
|
|
|
|
|
|
General Internal Medicine*
|
39 (60.9)
|
29 (51.8)
|
29 (46.8)
|
97 (53.3)
|
0.48
|
Emergency Medicine
|
7 (10.9)
|
9 (16.1)
|
12 (19.4)
|
28 (15.4)
|
Anesthesiology
|
0 (0)
|
1 (1.8)
|
1 (1.6)
|
2 (1.1)
|
Pulmonary and Critical Care
|
10 (15.6)
|
10 (17.9)
|
15 (24.2)
|
35 (19.2)
|
Cardiology
|
7 (10.9)
|
6 (10.7)
|
2 (3.2)
|
15 (8.2)
|
Other Internal Medicine subspecialty
|
0 (0)
|
0 (0)
|
0 (0)
|
0 (0)
|
Surgery/Surgical subspecialty
|
1 (1.6)
|
1 (1.8)
|
3 (4.84)
|
5 (2.8)
|
90-Day Experience†, No. (%)
|
|
|
|
|
|
0-10 patients
|
52 (65.6)
|
27 (48.2)
|
30 (48.4)
|
99 (54.4)
|
0.09
|
11-20 patients
|
14 (21.9)
|
15 (26.8)
|
17 (27.4)
|
46 (25.3)
|
21-30 patients
|
5 (7.8)
|
9 (16.1)
|
6 (9.7)
|
20 (11.0)
|
31-40 patients
|
2 (3.1)
|
2 (3.6)
|
3 (4.8)
|
7 (3.9)
|
> 40 patients
|
1 (1.6)
|
3 (5.4)
|
6 (9.7)
|
10 (5.5)
|
365-Day Experience†, No. (%)
|
|
|
|
|
|
0-25 patients
|
29 (45.3)
|
24 (42.9)
|
24 (38.7)
|
77 (42.3)
|
0.26
|
26-50 patients
|
22 (34.4)
|
16 (28.6)
|
12 (19.4)
|
50 (27.5)
|
51-75 patients
|
6 (9.4)
|
7 (12.5)
|
12 (19.4)
|
25 (13.7)
|
76-100 patients
|
4 (6.3)
|
1 (1.8)
|
7 (11.3)
|
12 (6.6)
|
> 100 patients
|
3 (4.7)
|
8 (14.3)
|
7 (11.3)
|
18 (9.9)
|
Device Used, No. (%)
|
|
|
|
|
|
Laptop/Personal computer
|
53 (82.8)
|
44 (78.6)
|
50 (80.7)
|
147 (80.8)
|
0.92
|
Mobile device
|
11 (17.2)
|
12 (21.4)
|
12 (19.4)
|
35 (19.2)
|
* Includes hospital medicine/hospitalist
† Experience managing patients with septic shock
‡ P values for overall category comparisons by intervention groups calculated using Kruskal-Wallis H test.
PGY = Post Graduate Year
Response Time and Guideline Discordance
Total-time was reduced in TC (45.8s, IQR 38.3s to 56.6s, P<0.001) and increased in COL (94.2s, IQR 73.0s to 142.6s, P=0.005) compared to control (71.5s, IQR 52.6s to 100.6s) (Figure 3A). Similarly, answer-time was also reduced in TC (9.5s, IQR 7.3s to 10.0s, P<0.001) and increased in COL (56.8s, IQR 35.9s to 86.7s, P<0.001) compared to control (28.3s, IQR 20.0s to 44.6s) (Figure 3B). There was no difference in read-time (TC=37.3s vs. COL=34.5s vs. control=34.6s, P=0.46).
Compared to guideline-concordant responses, guideline discordance was associated with reduced answer-time (45.0s, IQR 22.8s to 78.6s vs.16.3s, IQR 10.0s to 38.5s, respectively, P<0.001) and total-time (89.3s, IQR 55.6s to 130.2s vs. 62.6s, IQR 45.9s to 92.1s, respectively, P<0.001). Furthermore, there was a statistically significant overall relationship between choice architecture interventions and guideline discordance (c2 11.56, P=0.003). Using the binomial probability test, the proportion of guideline-discordant responses was increased from predicted in TC (78.6%, 65.5% to 87.6%, P=0.03) and reduced in COL (48.4%, 36.0% to 61.0%, P=0.01) assuming the control group’s probability (64.1%, 51.3% to 75.1%).
Time-to-Event Analyses for Competing Risk Endpoints
Cox proportional hazards regressions were performed to assess cause-specific differences in risk of guideline discordance between intervention groups. Proportional hazards assumptions were tested for all models and met (P>0.05) based on Schoenfeld residuals. Risk of guideline discordance was increased in TC (CHR 3.38, 1.97 to 5.79, P<0.001) and decreased in COL (CHR 0.52, 0.30 to 0.93, P=0.03) (Figure 4). Results were similar in TC (CHR 3.23, 1.80 to 5.82 P<0.001) and COL (CHR 0.54, 0.30 to 0.96, P=0.04) after excluding physicians in TC who failed to answer in the allotted time (n=8). Lastly, risk of guideline discordance was reduced among physicians with greater propensity to override intuitive thinking (high CRT score; ³2 of 3 correct answers) (CHR 0.56, 0.32 to 0.98, P=0.04) and among physicians who accurately identified the SSC initial fluid resuscitation guidelines (CHR 0.41, 0.19 to 0.90, P=0.03).
Effect Modification
CRT and both risk tolerance scales (JPI-RTS and MFS) were independently added as interaction terms to the adjusted main-effects Cox proportional hazards model. For the guideline-concordant endpoint, the effect of TC was dependent on CRT score while the effect of COL was dependent on risk tolerance by both JPI-RTS and MFS. For those with a high CRT score, the risk of a guideline-concordant answer was 7.87 (1.80 to 34.44, P=0.006) times higher in TC compared to control (Figure 4). In COL compared to control, risk of a guideline-concordant answer with a single standard deviation increase above mean JPI-RTS score (increased risk tolerance) or MFS score (decreased risk tolerance) was 2.0 (1.05 to 3.84, P=0.04) times higher and 0.42 (0.20 to 0.88, P=0.02) times lower, respectively (Figure 4). All interaction terms were non-significant for the guideline-discordant endpoint.
Measured Cognitive and Psychological Physician Characteristics
Immediately after answering the clinical vignette, self-reported acute stress compared to control was lowest in COL (5 vs. 3.5, respectively, P=0.002) with no significant difference in TC (4.5, IQR 3 to 6, P=0.23) (eFigure 1A). After adjusting for intervention group, accurate identification of SSC initial fluid resuscitation guidelines conferred the largest increase in odds of having higher stress (OR 2.39, 1.08 to 5.30, P=0.03) while reporting complete confidence in the selected answer to the vignette was associated with the largest decrease (OR 0.01, 0.00 to 0.06, P<0.001) (eTable 2). Additionally, mean CRT score was higher in TC among those who chose a guideline-concordant answer (2.42, ±0.19) compared to those who did not (1.98, ±0.14, P=0.007) (eFigure 3). Median confidence, JPI-RTS, MFS, and average CRT scores are further presented in the supplementary materials (eTable 3 and eFigure 1).
Several physician characteristics differed between men and women. Compared to men, women reported higher stress (5, IQR 3 to 7 vs. 4, IQR 2 to 6, P=0.001) and slightly lower confidence (3, IQR 2 to 3 vs. 3, IQR 2 to 4, P=0.03). Women also had lower propensity to override intuitive thinking and lower risk tolerance, as measured by the CRT (1.83, ±0.96 vs. 2.14, ±0.95, P=0.04) and JPI-RTS (18, IQR 14.5 to 21 vs. 20.5, IQR 17 to 24, P<0.001), respectively (eFigure 4).