The significance of each parameter included in the full model (with factors for five-second heartrate, biological sex, self-reported dizziness, and self-reported nausea) was compared to an intercept-only, null model. Inclusion of each factor (five-second heartrate, biological sex, self-reported dizziness, and self-reported nausea) significantly improved the model fit relative to the null model, $χdiff2(1)=6.08$, $p=.014$, $χdiff2(1)=6.12$, $p=.013$, $χdiff2(1)=21.51$, $p<.001$, $χdiff2(1)=23.84$, $p<.001$, respectively.1 The overall model resulted in a McFadden $R2=.74$, suggesting that our full model could explain 74% of the variability in the probability that a subject would drop out of the study. Please see Table 1 for exponent B values and significance levels. The area under a receiving operating characteristic curve (AUC) was determined to quantify the ability to discriminate between participants who dropped out and participants who remained in the experiment. This produced an AUC of 0.83. An analysis of five-second heartrate change revealed an increase of 15.5 bpm resulted in a participant having an equal probability of dropping out or remaining in the experiment. An increase of 4.5 self-reported nausea and 5.5 self-reported dizziness both on a scale of 1–10, also gave a participant an equal probability of dropping out or remaining in the experiment (see Figure 5). Females were more likely to drop out (n = 10); see Table 1.
Table 1.
Exponent B and Significance Values for Predictors
PredictorBS.E.Waldp
Heartrate 0.242 0.116 4.382 0.036
Change
Female (yes) −4.226 2.098 4.059 0.044
Dizziness 1.461 0.642 5.178 0.023
Nausea 1.307 0.583 5.036 0.025
Constant −6.834 3.660 −1.867 0.062
PredictorBS.E.Waldp
Heartrate 0.242 0.116 4.382 0.036
Change
Female (yes) −4.226 2.098 4.059 0.044
Dizziness 1.461 0.642 5.178 0.023
Nausea 1.307 0.583 5.036 0.025
Constant −6.834 3.660 −1.867 0.062

Note. df = 1.

Figure 5.

Probability of dropping out based on heartrate change from baseline and self-reported symptoms.

Figure 5.

Probability of dropping out based on heartrate change from baseline and self-reported symptoms.

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