A refined method for estimating the size of the potential blood donor pool in Australia.

BACKGROUND: To be eligible to donate blood, potential donors must meet certain eligibility criteria to ensure safety to the donor and to the blood supply. In Australia, there is no reliable estimate of the size of the donor-eligible population. This study uses a refinement to a published method to determine the population prevalence of donor-exclusion factors and subsequently estimates the size of the potential donor pool in Australia. STUDY DESIGN AND METHODS: A total of 70 donor-exclusion factors (in addition to age) were identified. The donor-eligible population was estimated by subtracting the prevalence of the exclusion factors from the total population. Prevalence of the donor-exclusion factors was adjusted for age, deferral period, and overlap of multiple conditions. Overlap was adjusted by extending a published random-probability model according to known association of epidemiologic data on overlapping conditions. RESULTS: The most prevalent (deferral period-adjusted) donor-exclusion factor among the 16- to 80-year-old Australian population was variant Creutzfeldt-Jakob disease-related travel risk (6.8%) followed by upper respiratory tract infections (6.4%). After exclusion of all factors, and accounting for overlapping factors, 62% of 16- to 80-year-olds or 47.3% of the total population were donor eligible in Australia. CONCLUSION: We developed a refined method for estimating the size of the donor-eligible population. Applying this method to Australia, we estimate that approximately 10.7 million people (62% of the 16- to 80-year-olds) were eligible to donate blood in Australia in 2012.

Understanding noncompliance with selective donor deferral criteria for high-risk behaviors in Australian blood donors.

BACKGROUND: Using a predonation screening questionnaire, potential blood donors are screened for medical or behavioral factors associated with an increased risk for transfusion-transmissible infection. After disclosure of these risks, potential donors are deferred from donating. Understanding the degree of failure to disclose full and truthful information (termed noncompliance) is important to determine and minimize residual risk. This study estimates the prevalence of, and likely reasons for, noncompliance among Australian donors with the deferrals for injecting drug use, sex with an injecting drug user, male-to-male sex, sex worker activity or contact, and sex with a partner from a high-HIV-prevalence country. STUDY DESIGN AND METHODS: An anonymous, online survey of a nationally representative sample of Australian blood donors was conducted. Prevalence of noncompliance with deferrable risk categories was estimated. Factors associated with noncompliance were determined using unadjusted and adjusted odds ratios. RESULTS: Of 98,044 invited donors, 30,790 donors completed the survey. The estimated prevalence of overall noncompliance (i.e., to at least one screening question) was 1.65% (95% confidence interval CI, 1.51%-1.8%). Noncompliance with individual deferrals ranged from 0.05% (sex work) to 0.54% (sex with an injecting drug user). The prevalences of the disclosed exclusionary risk behaviors were three to 14 times lower than their estimated prevalence in the general population. CONCLUSION: The prevalence of noncompliance is relatively low but our estimate is likely to be a lower bound. The selected high-risk behaviors were substantially less common in blood donors compared to the general population suggesting that self-deferral is effective. Nevertheless, a focus on further minimization should improve the blood safety.

Trends in transfusion-transmissible infections among Australian blood donors from 2005 to 2010.

BACKGROUND: Routine monitoring of trends in transfusion-transmissible infections (TTIs) is essential to maintaining and improving transfusion safety. Although periodic studies have been published there is no comprehensive trend analysis for TTIs in Australian donors. This study determined recent trends in TTIs for which testing is conducted in Australia and described key attributes of infected blood donors. STUDY DESIGN AND METHODS: This is a retrospective analysis using data on donation testing for TTIs (2005-2010) from the national blood service donor database and data on postdonation interviews with TTI-positive donors (2008-2010) from a risk factor database incorporating responses to standardized interview questions. The study measured the prevalence and incidence of TTIs in Australia and assessed their time trends. Multivariate analysis of time trends was conducted using Poisson regression models. RESULTS: Overall, the prevalence and incidence of TTIs in 2005 to 2010 remained low and steady. The prevalence of hepatitis C virus decreased (rate ratio [RR], 0.93; 95% confidence interval [CI], 0.89-0.97) and the prevalence of active syphilis increased (RR, 1.51; 95% CI, 1.15-1.99) significantly during the study period. Prevalence of TTIs among Australian blood donors was substantially lower than that in the general population and no unique risk factors were identified in test-positive blood donors when compared with the general population. CONCLUSION: Both the prevalence and the incidence of TTIs in Australian blood donors remained low, with a steady or declining trend for most infections except active syphilis. The lower prevalence of TTIs in blood donors compared with the general population reflects the effectiveness of donor education and donor selection measures in Australia.