The present study produced important and somewhat divergent findings. Overall, the two administration procedure of the HRQ produced largely comparable data with good to excellent inter- and intraclass correlation coefficients. At the same time, the TLFB procedure was associated with significantly greater self-reported risk behavior for two of the items (sharing any drug injection equipment and frequency of condom use during sexual activity), both of which constitute basic and important behavioral indexes of HIV transmission risks. Reliable and valid assessment of injection drug use and sexual behaviors is central to estimating the transmission risk of HIV and other blood-borne infectious diseases, and to evaluating the efficacy of substance abuse treatment and other more specific HIV prevention interventions. Findings from the study and its major implications for the field are discussed below.
4.1 Similarities and Differences in Frequencies of Self-Reported Risk Behaviors
The fact that the HRQ-Standard assessment method produced estimates of risk behavior very similar to those obtained using the more time consuming TLFB administration procedure deserves comment. It is impressive that the briefer interview approach produced data comparable to the TLFB method on most (80%) of the risk behavior domains. In general, this finding is consistent with prior research showing that other brief measures of cigarette, alcohol, and drug use correlate highly with estimates of the same behaviors collected using TLFB assessment procedures (Fals-Stewart et al., 2000
; Gariti et al., 1998
; Sobell et al., 2003
While the differences between administration procedures favoring the TLFB approach were modest in number (only 2 items), each of these behaviors are important summary indexes of HIV transmission risks (sharing of any drug injection equipment and frequency of condom use). For this reason, these differences are likewise worthy of some discussion. The modest findings favoring the TLFB approach are consistent with the view that this approach is associated with improved recall of retrospective self-reported behavior, including drug use and sexual activity (Carey et al., 2001
; Greenfield et al., 1995
; Hersh et al., 1999
; Weinhardt et al., 1998
; Maisto et al., 2008
). Also noteworthy is the fact that some studies have reported findings opposite to ours. For example, two studies (Carey et al., 2001
; Midanik et al., 1998
) found that more participants reported lower
frequencies of sexual behaviors using a TLFB assessment procedure compared to brief single item measures that did not use a timeline or event probes to facilitate recall of past behavior. Both of these studies, however, varied considerably from the present report with respect to sample, setting, and outcomes measures; differences that individually or combined might contribute to the discrepant findings.
4.2 Implications of Findings
These findings have both practical and important implications for treatment providers and programs, epidemiological and treatment researchers, and both local and national household surveys. Foremost among these is the fact that the present findings argue that a choice can be made for using one or the other assessment procedures depending on purpose for collecting the data. The importance of this choice is best revealed by the notable difference in the amount of time and effort each procedure requires to collect the information (staff training, administration time). The HRQ-Standard assessment procedure required substantially less interviewer training time and effort, and took an average of 6 minutes to administer, compared to about 30 minutes for the HRQ-TLFB approach.
While the HRQ-TLFB version was associated with increased reporting rates of one drug use and one sexual risk behavior category, this benefit must be weighed against the additional costs in staff training and instrument administration time incurred in using the TLFB version. The increased detection of risk behavior associated with the more time-intensive approach might be particularly valuable when HIV risk behavior is a central focus, for example, in studies specifically designed to determine the magnitude of risk behavior in a population and the extent of risk behavior change in response to one or more interventions. An additional advantage of the HRQ-TLFB version is that it provides more detail about the frequency of different types of drugs injected, types of sexual behaviors performed, and condom use during each type of sexual behavior. This information might be valuable in future studies designed to improve our understanding of the patterns of drug use and SRB, including event-level analyses examining the concordance of these behaviors.
In contrast, the HRQ-Standard measure might provide sufficient data when the goal is to obtain a good estimate of risk behavior as part of a broader focus on one or more other measures. For example, it could be useful as a screening tool for selecting persons for HIV risk reduction programs, when research in HIV risk behavior is not the primary outcome of interest, but possibly a predictor variable or covariate, as a brief index of risk behavior in substance abuse treatment settings, and an efficient and effective way to broaden coverage of this issue in national household surveys of health-related practices and problems.
4.3 Study Limitations
The results of this study must be interpreted in the context of some limitations. First, results relied on participants' self-report, a type of data that are inherently vulnerable to reporting errors and biases. However, self-report data is a standard measure for assessing HIV risk behavior. Another potential limitation results from the decision to always administer the TLFB assessment first rather than the HRQ Standard measure, or alternatively, counterbalancing their order of administration. This decision was based on the concern that the much more structured and detailed TLFB assessment would lead to greater carryover to the HRQ Standard assessment than the opposite order, and that this effect would not be offset by counterbalancing the administration of the two assessment methods. The absence of any pilot data supporting this concern is a weakness in the report.
The generalizability of the these findings may also be somewhat limited by the characteristics of the sample – an urban, low-income, and out-of-treatment injection drug users volunteering for participation in residential-based behavioral pharmacology studies. For example, results from this study may not generalize well to injection drug users seeking substance abuse treatment. However, a prior study that compared the characteristics of opioid-dependent treatment seeking patients to non-treatment seeking drug users enrolling in behavioral pharmacology studies in BPRU, where the present study was conducted, reported far more similarities than difference between the two samples on a wide range of demographic clinical variables and personality traits; hence, the generalizability of the present findings to samples of opioid users seeking treatment may be within acceptable limits.
The present study reveals important similarities and differences in the interview procedure used in the collection of HIV risk behavior. While the briefer and more commonly used interview approach in the collection of HIV risk behavior produced data more similar than different to the timeline followback interview procedures, important differences were observed on two basic indexes of drug use and sexual risk behavior risk that favored the TLFB interview method. The overall pattern of findings suggests that each of these interview approaches are reasonable choices, depending on the primary reason(s) for obtaining estimates of behavior associated with transmission of HIV and other blood-borne infectious diseases. The TLFB is a well-established methodology for the retrospective assessment of HIV risk behavior and is a good choice when quantitative precision and accuracy in the measurement of these behaviors is the primary focus of investigation. In situations where the major focus of work is on something other than HIV risk behavior, the HRQ-Standard measure appears to be a good choice.