Participants
People living with HIV/AIDS were recruited through targeted community sampling to participate in a cross-sectional study. We used both targeted venue recruitment and snowball sampling techniques to identify individuals in and out of care. Recruitment relied on responses to brochures placed in waiting rooms of HIV service providers and infectious disease clinics throughout Atlanta, GA. We also implemented an explicit systematic approach to word-of-mouth chain recruitment. Specifically, participants were given brochures that describe the study opportunity with a phone number to the research offices. Participants were encouraged to use the brochures to refer their HIV-infected friends to the study. These procedures were designed to extend recruitment beyond service settings in order to achieve a broad community sample of people living with HIV/AIDS. The entry criteria were age 18 years or older, scored at least 80% correct on a test of functional health reading literacy (TOFHLA) [18] and showed proof of their positive HIV status.
Measures
Measures were collected at the research site using an instructor guided self-administration procedure in groups of 4 to 8 persons. Participants were shown page by page how to complete the measures by using a projected facsimile, assuring that instructions for each instrument were carefully described and that participants were given privacy when responding. Data were collected between January 2008 and June 2009. Written informed consent was obtained from the participants of this study and the study was approved the university Institutional Review Board.
Demographic and health characteristics
Participants were asked their age, years of education, income, ethnicity, HIV treatment history, and employment status. HIV related symptoms were assessed using an adapted version of a previously developed measure [19], which included 14 common symptoms of HIV infection, including developing a new skin rash, recurring fever, chronic diarrhea, and persistent shortness of breath. We asked participants to provide blood specimens to test for HIV (RNA) viral load. Blood samples were provided at the project offices using standard phlebotomy and couriered to the lab for processing. Whole blood specimens in EDTA tube (Becton Dickinson) were centrifuged at 500 g for 10 min within 4 hrs of collection. The plasma was recovered and aliquoted into 1 ml samples and stored at -70°C. Plasma viral load was determined by Roche Amplicor HIV-1 Monitor.
Participants consented to monthly unannounced telephone-based pill counts, constituting a prospective measure of adherence. Unannounced pill counts are reliable and valid in assessing HIV treatment adherence when conducted in participants' homes [20] and on the telephone [21, 22]. Participants were provided with a cell phone that restricted service for project contacts and emergency use (e.g., 911). Following office-based training in the pill counting procedure, participants were called at unscheduled times by a phone assessor. Pill counts occurred over 21 to 35 day intervals and were conducted for each of the medications that participants were taking. Pharmacy information from pill bottles was also collected to verify the number of pills dispensed between calls. Adherence was calculated as the ratio of pills counted relative to pills prescribed, taking into account the number of pills dispensed. Two consecutive pill counts were necessary for computing adherence monitored for eight consecutive months. This study used the mean value of all available adherence data points as a stable indicator of HIV treatment adherence.
Dietary Supplements
We created an assessment of commonly used dietary forms of complementary medicine. We derived items for this measure through 3 sources. First, we selected dietary supplements described by the National Center for Complementary and Alternative Medicine. [Antioxidants, Chamomile & other teas, Flax seed, Macrobiotics, Probiotics, Selenium, St. Johns Wort] [1] Second, we identified additional items from previous research on the frequency of dietary supplement use among PLWH [Herbs] [4, 23] Finally, we held informal discussions with ten people living with HIV who participated in past research regarding their experience with dietary supplements. [Amino acid therapy, Immunotherapy, Micronutrient therapy, Orange juice pills, Chinese medicine, African medicine] The final result was 14 dietary supplements. Participants were presented with the list of dietary supplement practices and instructed to mark each for whether they (a) had ever used it since testing HIV positive and (b) whether they were currently using it. We also asked participants who reported current use of dietary supplements to estimate the amount of money they spend per month on these products.
Dietary Supplement Beliefs
We assessed participants beliefs regarding the benefits of dietary products for curing HIV infection and AIDS. Participants completed 4 items regarding vitamins, traditional and herbal remedies, and immune boosters. The exact items are shown in the results section. Items were responded to as 'Agree' and 'Disagree'.
Internet use for health-related information
Participants indicated whether they had used the Internet to find health-related information, purchase health products, and shared health information they had accessed online. Participants reported the number of times they had used the Internet for these purposes in the previous month. Open responses were collected by participants writing values in blank spaces for the number of times they performed each action.
Perceptions of e-health information
We assessed perceptions of unsubstantiated claims available on the internet regarding the use of dietary practices to treat and cure AIDS. Participants completed an internet rating task adapted from previous research [24, 25]. For this task, webpages were obtained directly from the Internet, including color, image resolution, and text size. We selected two webpages representing false claims for using micronutrients to treat and cure AIDS: (a) Rath International: "Micronutrients Help Control AIDS"http://www4.dr-rath-foundation.org/pdf-files/ri_2006_02_en.pdf summarizes the findings from uncontrolled studies that have been deemed unauthorized and illegal[12, 13]. The specific webpage reports 'clinical proof' that micronutrients improve the health of PLWH and that antiretroviral medications are toxic and without benefit; (b) Jonathan Campbell; "A Cure for AIDS?"http://www.cqs.com/aidscure.htm endorses the use of "immune system enhancing nutrients such as vitamin C (in absolutely massive doses) and zinc". This webpage states that the pharmaceutical industry promotes "drugs such as AZT that focus on destroying HIV (meanwhile killing the patient)".
One reputable website was included as a control: Tufts School of Medicine "Choose Snacks that work for you"http://www.tufts.edu/med/nutrition-infection/hiv/health_snacks.html explains the nutritional value of healthy snacks and the benefits from healthy food choices.
As a check for whether participants had read the internet passages, we asked three factual true/false questions extracted from the text of each passage. Participants also indicated their perceptions of and interest in the three sources of information by rating four dimensions: "How much do you believe this information?", "How factual is the information?", "How much do you trust the information?" and "How important is this information for you?" using 10-point scales ranging from 1 = 'Not at all' to 10 = 'Very much'.
Data analyses
We performed descriptive analyses to examine the frequency of past and current use of 14 dietary supplements separately for men and women. We then compared current dietary supplement users (N = 93) to PLWH who were not currently using dietary supplement (N = 251) on demographics, health characteristics, internet use, perceptions of website information, and dietary supplement beliefs. Comparisons on continuous measures used independent groups t-tests and categorical variables were analyzed using contingency table chi-square tests. We performed a final multivariable logistic regression analysis to test the independent effects of factors related to current dietary supplement use. This multivariable model simultaneously tested non-overlapping factors from the previous analyses found significantly associated with current dietary supplement use. To avoid statistical redundancy we created a total index of interest and believability of the Rath and Campbell website claims regarding treating and curing AIDS. Specifically, we calculated the mean score of the four interest and believability ratings. In addition, we created a composite of the four dietary supplement beliefs by summing the endorsements, ranging from 0 endorsed to 4. From the logistic regressions we report odds ratios with 95% confidence intervals. All analyses used case-wise deletion for missing values and defined statistical significance as p < .05.