Psychometrics

Studies conducted by the authors and others suggest that when properly administered, the RAB responses are equivalent to those collected via personal interview. Test-retest reliability has also been found to be relatively high. Importantly, the RAB has demonstrated discriminant validity in differentiating between respondents engaging in different drug use patterns and predictive validity in identifying seroconverters on the basis of higher risk scores.

Internal consistency

  • Drug risk score: Cronbach alpha = .82
  • Sex risk score: Cronbach alpha = .42

Factor/cluster analysis

  • Factor structure was examined in developing drug and sex risk scales

Reliability

Test-retest

Population Drug Risk Sex Risk
Methadone .80 .69
Cocaine .73 .88

Inter-method Comparison: NIDA AIDS Follow-up Assessment [AFA] and RAB

Item % Reporting on RAB % Reporting on AFA Exact Agreement Phi Kappa
Drug Risk          
Injected 62.7 63.5 96.5 .93 .93
Shared Syringes 18.9 16.9 94.5 .81 .81
Shared w/ Multiple IDUs 4.7 4.5 96.6 .61 .61
Shared Cotton 30.6 25.1 88.9 .76 .75
Shared Cooker 34.1 33.6 92.7 .84 .84
Shared Rinse Water 28.1 24.4 88.5 .70 .70
Sex Risk          
Sex w/ Multiple Partners 24.5 24.3 96.6 .91 .91
Always Use Condoms 28.9 20.4 85.8 .64 .62

Construct Validity

  • Significantly higher drug risk scores for methadone program patients as compared to cocaine users in treatment
  • Significantly higher sex risk scores for cocaine users as compared to IDUs

Predictive Validity

  • Compared risk scores of IDUs who seroconverted at any time point with IDUs who remained seronegative; by follow-up month (M)

IDUs Who Remained Seronegative by Follow-up Month

RAB Seroconverted 12M 18M 24M 30M 36M 42M 48M
Risk Score n=17 n=137 n=140 n=139 n=137 n=135 n=137 n=142
Drug Risk 5.75 3.31* 2.66* 2.27* 1.99* 2.27* 2.23* 1.84*
Sex Risk 5.18 4.18 4.05 3.67 3.60 3.31* 3.34* 3.13*
RAB Total 10.94 7.59* 6.74* 5.96* 5.64* 5.61* 5.59* 4.59**

* p<.05; **p<.005


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