Similar to the results described in other reports, our health system saw an unexpected increase in the number of oseltamivir prescriptions during fall 2005, which suggested personal stockpiling.2
Review of electronic medical records in conjunction with questionnaire responses confirmed that the majority of prescriptions were provided to persons concerned about avian influenza. This is not surprising, given the reported 300% increase from 2004 to 2005 in national sales of oseltamivir during the fall months2
and the fact that nearly half of all infectious diseases specialists surveyed reported that they had been asked for an oseltamivir prescription for personal stockpiling.3
In recent history, there has been a similar public response to biological threats. Following the events of September 11, 2001, and the ensuing anthrax attacks, ciprofloxacin was widely prescribed and the number of prescriptions was out of proportion to the number of individuals potentially exposed; this was true even in geographic regions of the United States where anthrax cases and/or exposures had not occurred.4–6
One concern related to personal stockpiling is the inappropriate use of stockpiled drugs for self-diagnosed ailments.7
Several groups have documented high rates of self-medication with antibacterial drugs for apparent viral upper respiratory tract infections, without physician consultation.8–10
Drugs that are originally prescribed for a presumed bacterial illness are commonly not completely consumed, and the remaining pills are then consumed later when the patient has a cough or sore throat.8–10
Very little of the oseltamivir not intended for immediate use was taken later by our study cohort. Ongoing concerns about an outbreak might have resulted in preservation of the oseltamivir for future use, or perhaps patients are less familiar with antiviral drugs and were reluctant to consume oseltamivir. Alternatively, the prescriptions for oseltamivir may not have been filled. Although we did not intend to determine the rate at which prescriptions were filled and did not address this issue in our questionnaire, several healthcare providers documented that their patients would not fill the oseltamivir prescription unless needed, and several questionnaire respondents specifically indicated that they did not fill their prescription. Regardless, inappropriate and unsupervised use of “leftover” drugs may not be as problematic for oseltamivir as it has been documented to be for antibacterial medications.
Not surprisingly, individuals likely to stockpile oseltamivir reported greater worry about avian influenza than did control subjects, and more of them reported the expectation that avian influenza would spread to the United States. Among those likely to stockpile, we also found a nonstatistical trend toward greater pessimism regarding the probability of being affected by the disease. However, there were few statistically significant differences in the responses to other questionnaire items, particularly those relating to individuals’ knowledge and understanding of avian influenza. Both groups were unable to answer a large proportion of the questions, either because of a lack of knowledge or because of uncertainty about their estimations and opinions. It is worth noting that there was a substantially lower number of “don’t know” responses to questions pertaining to the United States’ pandemic preparedness, with both case patients and control subjects demonstrating a clear lack of confidence in the government’s readiness. Surprisingly, answers to several questions actually reflected underestimation of the potential ramifications of a human pandemic. For example, both case patients and control subjects most often reported that the human case-fatality rate associated with avian (ie, H5N1) influenza virus infection was less than 25% when, in fact, the mortality rate is greater than 60%.11
Similarly, after “don’t know,” both groups most often responded that people they knew or cared about would not become infected or die during an outbreak. In contrast, an estimated one-third of the world’s population was infected during the 1918 influenza pandemic. With a case-fatality rate of more than 2.5%, at least 50 million people died.12
Taken together, these findings suggest that the differences between case patients and control subjects that may have led to personal stockpiling reflect differences in individuals’ personalities and their degree of apprehension about avian influenza, rather than differences in their basic knowledge. Differences in the number of interactions with their healthcare providers and access to, familiarity with, and/or level of comfort with their physician and/or the healthcare system may have also played a role in determining who stockpiled the drug and who did not. These results suggest that patient education and/or increased communication from public health officials may not have been effective in curtailing demand from persons who wished to stockpile oseltamivir for their personal use. This is especially true given that the case-fatality rate for H5N1 influenza virus infection and the potential for widespread infection were underestimated by respondents and the fact that public officials are not able to guarantee an adequate supply of antiviral medication. Thus, education of healthcare providers, in concert with the development of national and local guidelines and official recommendations regarding personal stockpiling, may be more effective by decreasing the number of providers willing to prescribe medication in situations in which stockpiling is considered an inappropriate use of a scarce resource. A recent report supports the need for such guidance.3
Suggestions about how to counsel and advise concerned and demanding patients may also be beneficial. Because a large proportion of both case patients and control subjects responded “don’t know” to many questions, however, open dialogue with patients about the current status of infectious threats may also be worthwhile.
Our study had several limitations. As in all surveys, our data may be subject to nonresponse bias, although there were no significant differences between those who responded and those who did not with respect to basic demographic characteristics. In addition, recall bias cannot be excluded, and patient responses most certainly reflect knowledge and thought processes at the time of questionnaire administration rather than those that occurred at the time the oseltamivir prescription was obtained. The high proportion of patients who responded “don’t know” to certain questions may have limited our ability to detect differences between case patients and control subjects for those questions, but nonetheless highlights similar uncertainty in both groups. Our study also may have been underpowered to detect modest differences between case patients and control subjects for some survey questions. The assessment of indications for oseltamivir was limited by our use of a retrospective record review. Finally, we could not determine that all prescriptions for which the indications were not clearly elucidated were definitely intended for personal stockpiling. In particular, 4 individuals classified as probable stockpilers responded that they were not at all worried about avian influenza and that avian influenza would never come to the United States. Analyses were performed that excluded these individuals, and the results were not substantially different. However, with respect to other case patients, the widespread reports of stockpiling around the country, the lack of a documented appropriate indication, and the absence of similar prescriptions during the prior influenza season for all persons in this group suggest that stockpiling is likely to have occurred.
Future outbreaks of emerging infectious diseases and the possibility of bioterrorism are, at the present time, unavoidable. By evaluating the receipt of oseltamivir prescriptions prior to the onset of influenza season and during a period of heightened media coverage of avian influenza, our study is the first we know of that closely examines, on a patient-specific level, the attitudes associated with personal stockpiling. Although personal stockpiling was common, subsequent consumption of oseltamivir for inappropriate reasons was not. In a comparison of case patients and control subjects with respect to their knowledge, beliefs, concerns, and expectations regarding avian influenza, we found very few differences between persons who stockpiled oseltamivir and those who did not. Although our findings may not apply to all stockpiling scenarios, they suggest that there may be few patient-specific modifiable factors associated with stockpiling of antimicrobials and that self-medication with stockpiled drugs need not be a major concern in all circumstances. Strategies aimed at limiting prescribing by healthcare providers may be a more effective approach for minimizing personal stockpiling in instances where resources are scarce. The results of this study provide information that may be useful in formulating a public health response to other emerging infectious diseases and/or bioterrorism scenarios that prompt a high demand for antimicrobials.