| Background: Nonrandomized response (NRR) models are a new generation of surveys for sensitive
issues. This study aims to evaluate the validity of estimates from the crosswise model (as
one of the efficient models) through employing different response probabilities of nonsensitive
questions. Methods: This cross-sectional study was conducted during October and November
2015 among 1777 students of Tabriz University of Medical Sciences. Estimates of monthly alcohol
consumption, and at least one instance of illicit drug use and extramarital sex over the last
year were determined using direct questioning (DQ) and the Crosswise model (CM). In the last
model, the probability of positive response to the nonsensitive questions was determined by
using five different methods: uniform distribution (I), Benford’s law (II), and estimations based
on data from three other studies (III, IV, V). Results: Crosswise estimates of sensitive behaviors
with different probabilities of a positive response to nonsensitive questions differed significantly.
For example, estimates of history of using illegal opioids at least once in the last year
among men varied significantly from 5.0% to 16.1% with different crosswise models based on
the probability of being born in Spring using method I (0.250), III (0.287), IV (0.248), and V
(0.310). The model based on Benford’s law (II) was applied to estimate alcohol and cannabis
consumption, and its estimates showed significant discrepancy with results of crosswise models
I and V. Conclusion: Estimates from crosswise model is highly sensitive to the response probability
of nonsensitive questions. It seems that if this question is not selected carefully, the
mentioned models will provide overestimates or underestimates, and the more-is-better
hypothesis is not always valid. To achieve valid estimates, the exact probability of |