Donor screening strategies enhance safety[13
] of blood but only few have been evaluated for effectiveness before implementation[14
] Some predonation screening procedures are of questionable significance, especially after introduction of TTI screening tests of high sensitivity and specificity.[16
] Developing countries like Pakistan are faced with challenge of extending same standard of care as developed countries, but have poor infrastructure, nonsustainable health care funding, illiteracy and uninformed public, and above all absence of evidence for formulation of locally relevant policies. It has been seen that screening policies, predonation, and others that have evolved in developed countries is made part of local regulatory guidelines, which may not be relevant, practical, or affordable in present conditions. Some of these may have adverse impact on the transfusion services and therefore need for local evidence is urgent. This study tries to fill one of the gaps about effectiveness of donor health history questionnaire as a tool to defer unsafe donor, who are more likely be in window period of TTI. Seven questions are initially tested which were framed in simple, easily understandable language that could be answered without assistance, and are based on risk factors[5
] that have been systematically reviewed by Syed et al
] The cases and controls were a cohort of directed donors/replacement donors.
The introduction of educational material and direct questioning about HIV risk factors has been effective in decreasing risk of its transmission before tests for HIV were available.[18
] This study, however, did not include questions directed towards HIV and illicit drug use related high risk behavior because piloting of such risk directed questions in same center showed that no such question were answered by the donors. The reasons could be that directed and replacement donors completed the questionnaire with their relatives and friends around them and they probably did not trust the privacy and confidentiality of information with the blood bank. Social and religious taboos to answer such questions even to health care workers is well known in the society as exemplified by the denial of high risk behavior by the donors who tested positive for syphilis, even on one to one interview. Failure to acknowledge risk behavior is complex in every society, and some degree of nondisclosure is expected in predonation screening.[19
] Nonvolunteer donors selected as subjects were the important limitation of the study; therefore, the results may not be completely applicable to all volunteer donors. However since the questions were taken as not crossing the threshold of privacy of donors, and were answered enthusiastically, therefore the author concludes that these will be applicable to all types of donors.
Tables and ORs for any risk factor did not prove significant association of risk factors with seroreactivity for hepatitis in this study. Previous history of jaundice irrespective of age for HBV and history of surgery in previous 6 months for both HBV and HCV had PPV of 20% or more [Tables and ]. The calculations were based on pretest probabilities of 7% derived from the weighted averages of hepatitis prevalence in Pakistani blood donors.[12
] The post-test probability of hepatitis was increased to 30% for these questions, which makes these two questions having highest efficacy and therefore are recommended to be part of Donor History Questionnaire (DHQ) and used for deferring donor. Similar observation has been made by Zou et al
., who found that questions regarding risk of viral hepatitis and history of intravenous drug use, correlated better with hepatitis markers positive donors.[20
] Permanent deferral is recommended for Pakistani donors having history of jaundice at any age because 40% of HBsAg in Pakistan is acquired in perinatal period,[9
] which will be in contrast to USA where history of jaundice after 11 year age is criteria for permanent deferral. Donors with history of surgery should be temporarily deferred for 1 year which is sufficient time for seroconversion after last intervention especially if screening is done with reagents of high sensitivity and is similar to what is being recommended by Federal Drug Agency USA and American Association of Blood Banks.[21
The 5.3% deferral rate is expected to be lower if DHQ comprising seven questions is implemented because some donors with viral markers will be excluded in predonation screening. However, the ORs in this study have shown that there is no significant association of risk factors with TTI; therefore, this seropositivity rate will persist and will have to be added to other causes of donor deferral and sums up to 20% of all donors at the center. This seems to be excessive when compared with 14% in USA where donors are asked more than 40 questions and takes into consideration the miscollected units as well.[22
It is important to note that one fourth of donors in this study needed assistance to fill up the questionnaire because of illiteracy or primary education alone. This has implications for introducing “self exclusion” policy in this country in which donor decide to refrain from donation after comprehending the educational material about risks of donations from high risk donors. Therefore, either the volunteers will have to be recruited from educated classes or primarily audiovisual techniques will have to be applied.
This type of study or those employing different strategies need to be duplicated in all volunteer donors who are provided adequate privacy and have assurance about the confidentiality at blood bank. Such studies may be supplemented with anonymous donor surveys to assess the magnitude of high risk donors and truth challenged donors. Sexual behavior/preferences and drug intake directed questions need to be assessed as well to define effective donor health questionnaire that are more likely to defer donors in window periods of TTIs and could not be undertaken in present study. For hepatitis-related questions, this present study is sufficient to extrapolate results to other groups of donors and may form basis of much abbreviated questionnaire until more studies are available.
Since none of donors in study happen to have history of transfusion, therefore its PPV could not be calculated. However, this is important risk factor for hepatitis in our country as shown in many studies[12
] and although only minority of donors will probably become volunteer donor after having indications to receive blood transfusion, therefore this history should also constitute criteria for temporary deferral as is also approved by FDA and AABB[21
] Only limited number of questions should be made as donor deferral criteria at donor interview and should explicitly be stated in the national guidelines, keeping in view the structural, organizational, and financial limitations of country.[24
] TTIs for which laboratory test are not yet available, DHQ remains the only way to defer donor with high risk [e.g., Creutzfelt Jacob Disease (VJD), variant CJD], however surveillance of blood transfusion recipients and epidemiological data for such infections, should be available for the country before introducing deferral policies, directed at these even if they are deemed effective for other countries.
In an era of very effective and sensitive laboratory testing for TTI, the developing countries should set their priorities on evidence and not necessarily have to adopt non evidence-based policies based on precautionary principle only. The meager resources should be primarily directed at ensuring universal screening for TTI with high quality reagents, at grass root level.