rent transfusion practices, identify changes in practice that have occurred since the 1981 survey, and determine the need for future educational endeavors, the ASA Committee on Transfusion Medicine conducted a survey of active ASA members in 2002. We also sought to determine whether members were familiar with the ASA Practice Guidelines for Blood Component Therapy (hereafter referred to as the ASA Guidelines) published in 1996 19
and whether they seemed to be following them.
Materials and Methods
The majority of the survey questions were identical to those on the previous survey so that the responses could be compared. Some questions were modified to incorporate responses based on the ASA Guidelines. Questions regarding the frequency of administering transfusions, the criteria for reinfusing predonated autologous blood, the use of whole blood, and intraoperative performance of hemoglobin determinations and coagulation tests were added. Demographic data regarding the member's practice location, years in practice, type of practice, and certification were included.
After institutional review board approval, the survey was mailed to 2,500 randomly selected active members of the ASA, representing approximately 10% of the active membership. A power analysis before performing the survey revealed that 750 respondents would result in an approximate precision for point estimates of ± 3.7% based on the half-length of a 95% confidence interval assuming a point estimate of 50%. We assumed a 30% response rate. Therefore, 2,500 surveys at a 30% response rate would result in 750 survey responses. The randomization was performed with use of a computer. Resident, affiliate, honorary, life, and retired members were excluded. The identity of respondents remained anonymous.
The number of respondents (i.e., the denominator used to calculate the percentage response) dictates the precision of the corresponding point estimate. With 862 responses, the approximate precision for point estimates is ± 3.4% based on the half-length of a 95% confidence interval assuming a point estimate of 50%.
The percentages should total 100 within round-off error and excluded those who left the question unanswered or indicated that it was not applicable. In some questions, more than one answer could be given (Appendix 2
, questions 5, 7, 9, 10, 11, 13, 15, 23, 25, and 32). We analyzed those questions on an individual response basis, and the total percentage response may be greater than 100%. In cases where additional questions are asked after an initial response, the percentage responses for the follow-up question were reported based on the total number of initial question responses (Appendix 2
, questions 6, 8, 26, 27, and 28). For these follow-up questions, the total percentage may be less than 100% if responses were missing or greater than 100% if more than one answer could be given.
There were 389 respondents for the 1981 survey. Comparisons of 2002 to 1981 were made using the chi-square test for equality of endorsement percentages. In all cases, two-tailed P values of 0.05 or less were considered evidence of differences not attributable to chance.
Of the 2,500 questionnaires mailed, a total of 1017 surveys were returned, for a 41% response rate. Of these, 862 respondents provided or directly supervised anesthesia for patients who required transfusion. Further analysis was based on this population of 862 anesthesiologists. A copy of the questionnaire is attached as Appendix 2
The majority of respondents never or rarely (62%) or only one to five times a week (37%) transfused 3 or more units of blood to the same patient in a typical workweek. There was a change in the profile of the physician considered primarily responsible for ordering and administering blood products intraoperatively. In 1981, 53% said the anesthesiologist was responsible, 2% said it was the surgeon, and 45% considered it a joint responsibility. The responses in 2002 were 33%, less than 1%, and 67%, respectively (P < 0.001).
The percentage of survey respondents certified by the American Board o