Due to an error in data coding, tables 1–3 are replaced by the following. The Corrigendum Note below each table explains the error and correction.
NPV, Negative predictive value: probability of (−) laboratory drug tests and (−) self-rated assessments; PPV, positive predictive value: probability of (+) laboratory drug tests and (+) self-rated assessments; SENS, sensitivity: proportion of (+) laboratory drug tests and (+) self-rated assessments; SPEC, specificity: proportion of (−) laboratory drug tests and (−) self-rated assessments; ‘Any use’ indicates the use of cocaine, cannabis or methamphetamine; laboratory drug test (+/−) includes urine drug test results and radioimmunoassay (RIA) of hair test results.
Corrigendum Note . The findings presented in this updated version of Table 1 are not qualitatively different from the results that were previously reported in error. This updated version of Table 1 shows 28% of the overall sample tested (+) for any drug use, and drug use under-reporting was observed for 44% of the participants with (+) laboratory drug tests.
PANSS, Positive and Negative Syndrome Scale; ITAQ, Insight and Treatment Attitudes Questionnaire; S.D., standard deviation; CPZ, chlorpromazine equivalent dose (CPZ daily dose equivalents were computed based on prescribed typical and/or atypical antipsychotic medications).
Corrigendum Note. As indicated in this updated version of Table 2, a greater proportion of women under-reported drug use as compared to men, but this finding is now a trend and is not significant at conventional thresholds. The other findings that are reported in this version of Table 2 are not qualitatively different than the results that were previously reported in error.
PANSS, Positive and Negative Syndrome Scale, S.E., standard error; OR, odds ratio.
a OR represents a 10-year change in age.
Corrigendum Note. Compared to the results that were previously reported, the findings reported in this updated version of Table 3 suggest that positive symptomatology is a significant predictor of the under-reporting of cannabis use. The updated results also indicate that age is a significant predictor of the under-reporting of cocaine use. There are no other qualitative differences of mention between this version of Table 3 and the results that were previously reported in error.