- Email: [email protected]
National Survey of Dietary Supplement Resources at Drug Information Centers
RESEARCH
National Survey of Dietary Supplement Resources at Drug Information Centers Kelly M. Shields, Cydney E. McQueen, and Patrick J. Bryant
Received April 21, 2003, and in revised form June 19, 2003. Accepted for publication August 4, 2003.
ABSTRACT
Participants: 116 drug information centers.
Kelly M. Shields, PharmD, is Assistant Clinical Professor and Assistant Director, Drug Information Center, Raabe College of Pharmacy, Ohio Northern University, Ada. At the time this research was conducted, Shields was natural product information and research fellow with the University of Missouri Kansas City Drug Information Center, Kansas City, Mo. Cydney E. McQueen, PharmD, is Assistant Director, Drug Information Center, and Clinical Assistant Professor; Patrick J. Bryant, PharmD, is Director, Drug Information Center, and Clinical Associate Professor, School of Pharmacy, University of Missouri–Kansas City.
Interventions: Mail survey that collected information on the use of drug information centers for dietary supplement information requests and the dietary supplement-specific resources available at and used in these centers.
Correspondence: Cydney E. McQueen, PharmD, Drug Information Center, University of Missouri–Kansas City, 2411 Holmes, Suite MG-200, Kansas City, MO. 64108. Fax: 816-235-5491. E-mail: [email protected].
Main Outcomes Measures: Survey responses, evaluated using descriptive statistics.
Disclosure: The authors declare no conflicts of interest or financial interests in any product or service mentioned in this article, including grants, employment, gifts, stock holdings, or honoraria. Shields and McQueen have served as content reviewers for Natural Medicines Comprehensive Database.
Objective: To assess the resources drug information centers are currently using to respond to dietary supplement information requests and to determine the frequency with which drug information centers are used as sources of information on dietary supplements. Design: Cross-sectional survey. Setting: United States.
Results: Drug information centers received a relatively small number of requests for information related to dietary supplements, and most such requests came from consumers. The centers had a number of resources available to assist in responding to those requests, with Facts and Comparisons’ The Review of Natural Products and the print version of Natural Medicines Comprehensive Database being the resources most often at hand. The majority of respondents believed their centers were “usually able” to respond to the requests received.
Presented previously at the American Pharmaceutical Association Annual Meeting, March 31, 2003, New Orleans, La.
Conclusion: Drug information centers are often overlooked as sources of information about dietary supplements; however, centers have resources that are, by self-assessment, sufficient to respond to dietary supplement information requests. Great variation exists among centers in the resources available to address requests, with just two resources, the Review of Natural Products and the print version of Natural Medicines Comprehensive Database, available to more than three-fourths of the respondents. Keywords: Dietary supplements, drug information centers, information sources, natural products. J Am Pharm Assoc. 2004;44:36–40.
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T
he increased use of dietary supplements over the past decade in all patient populations has been well documented.1,2 Yet, for reasons that remain unclear, the majority of patients are not informing health care practitioners of their use of these products.1 Possibly, patients perceive dietary supplements as “natural” and therefore safe, or they may believe that health care practitioners have negative attitudes toward or are not well informed about dietary supplements. Even though the majority of patients are not discussing supplement use with practitioners, due to the increasing volume of use, practitioners are nonetheless likely receiving more requests for information about dietary supplements. Drug information centers would, therefore, likely see corresponding increases in questions on supplements. This change is difficult to assess globally because no studies evaluating the number of dietary supplement information requests centers receive from health care practitioners have been reported to date, and, therefore, baseline numbers are not available for comparison. Results of one recent survey indicate that fewer than 10% of pharmacists contact drug information centers when they have questions about dietary supplements.3 Pharmacists may be hesitant to rely on these resources for information on supplements to the same extent that they do for information about medications because they perceive that centers lack the resources, expertise, or desire to provide information regarding dietary supplements. While previous studies have assessed trends in the growth of drug information centers and looked at the services they pro-
AT A GLANCE Synopsis: Despite the huge increase in use of dietary supplements by the American public over the past decade, drug information centers are receiving relatively small numbers of requests for information about these products. According to the results of this national survey of drug information centers, consumers are more likely than health professionals to ask questions about dietary supplements. The centers use a variety of reference materials to respond to such queries, with printed materials being the most commonly available source of information. However, centers are more likely to use Web-based references, despite the wider availability of printed materials. Analysis: Other published studies show that poison control centers receive a fair number of calls about adverse effects of dietary supplements, but consumers and health professionals do not often turn to drug information centers for information about these products. Given the wealth of knowledge and expertise available in drug information centers, there should be greater use of this resource for information on herbal products, vitamins and minerals, and other dietary supplements.
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vide,4–7 few have assessed the resources of these centers,4,5 and none has evaluated which specific dietary supplement resources are held by drug information centers.
Objectives We undertook this survey to assess the resources drug information centers are currently using to respond to dietary supplement information requests and to determine the frequency with which drug information centers are used as sources of information on dietary supplements.
Methods We sent notification letters to the directors of the 116 drug information centers identified in the 2002 Red Book,8 informing them that a survey would follow 1 week later. The survey was then sent to the same centers along with a cover letter explaining the purpose of the survey and requesting it be returned via fax or in an enclosed self-addressed, stamped envelope. Surveys were coded so that a second survey could be sent to nonresponders. The survey period was November 2002 through January 2003. Two weeks after the first mailing, we sent a second copy of the same survey instrument and completion instructions. Surveys returned within 30 days after the second mailing were included in the results. The survey instrument gathered descriptive data, including institutional information, dietary supplement information sources the center currently used, dietary supplement resources available in the center, and a self-evaluation of the center’s ability to respond to requests. If respondents selected multiple responses to the same question or returned two surveys, only the first response or survey was used. We made no attempts to contact respondents to clarify responses or obtain incomplete or missing data. Survey data were tabulated using SPSS version 11.0 (Chicago, Ill.). Statistical tests included mean, average, and χ2. The project was approved by the University of Missouri− Kansas City Social Sciences Institutional Review Board.
Results We received 49 responses to the initial mailing. One survey was returned due to an incorrect address. We received 18 additional responses to the second mailing. Thus, a total of 67 responses were received, for a response rate of 57.8%. Because one survey was returned without any data recorded, the number of usable surveys was 66 (56.9%). Results from eight surveys received after the 30day deadline were not included in the data analysis. Responding centers were most often affiliated with a hospital (50.0%), followed by college of pharmacy (28.8%) and medical
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Dietary Supplement Resources
center (15.2%). The number of full-time drug information specialists on staff at responding centers ranged from 1 to 4, with 51.5% having only 1 full-time drug information specialist. Most of the responding centers—65.2%—reported no additional training for drug information specialists in the area of dietary supplements, while 22.7% indicated that “dietary supplement training” consisted of a continuing education program on the topic. The average number of drug information requests received monthly ranged from 51 to 100. Respondents indicated that most drug information requests came from pharmacists (42.4%) and physicians (31.8%). Dietary supplement requests, on average, accounted for a mean ± standard deviation (SD) of 7.8% ± 6.4% (range, 0.5%−25.0%) of all requests. A positive correlation was found between the number of drug information requests and the number of dietary supplement requests, indicating that, proportionally, the busiest centers received the most requests relating to dietary supplements. Most dietary supplement information requests came from consumers (30.3%), followed closely by nurses and other health care practitioners (see Figure 1). Requests from pharmacists and physicians lagged far behind, at 7.6% and 4.5%, respectively. Of the 30 resources listed in the survey, the most commonly held dietary supplement resources were Facts and Comparisons’ The Review of Natural Products9 and the print version of Natural Medicines Comprehensive Database.10 Seven resources were held by more than one half of the respondents. The 10 most commonly reported resources are listed in Table 1. The other resources were held by fewer than 10% of respondents. Respondents also listed the dietary supplement resources most commonly used (as opposed to held) in their practice setting. The resource most commonly used was the online version of Natural Medicines Comprehensive Database16 (36.4%), followed by AltMedDex System13 (16.7%) (see Table 2). Most respondents indicated they are “usually able to respond” Figure 1. Percentages of Queries Received from Various Groups About Dietary Supplements at 66 Drug Information Centers 35 30
30.3
Discussion It appears that many health care practitioners are not making use of the resources available at drug information centers when responding to dietary supplement information requests. The very small number of dietary supplement requests (7.6%), as opposed to general drug information requests (42.4%), the centers reported receiving from pharmacists could be explained to some extent if pharmacists were directly referring patients to these centers. If this were true, then the large number of requests from consumers would be expected. However, based on handwritten notes on survey responses, some drug information centers do not accept requests directly from consumers; therefore, this reason cannot fully explain the unexpectedly high consumer usage and low pharmacist usage of the centers as resources for information on dietary supplements. Interestingly, the portion of dietary supplement information requests received from all requesters was small compared with the number of general drug information requests received. Several factors could explain this difference. Possibly, requesters did not believe drug information centers would have sufficient resources to respond to their requests. Our results should help alleviate this concern. Another explanation may be that questions about dietary supplements are being directed to poison control centers rather than drug information centers. Palmer et al.20 examined the number of dietary supplement ingestion reports handled by poison control
Table 1. Most Commonly Held Dietary Supplement Information Resources at 66 Drug Information Centers Resource
25.8
25
(63.6%) or “always able to respond” (22.7%) to dietary supplement information requests. The remaining 12.1% were “sometimes able to respond.” We found no statistically significant correlation between centers with personnel having additional dietary supplement training and respondents’ ratings of their ability to respond to dietary supplement information requests (P = .82).
22.7 20 15
78.8
Natural Medicines Comprehensive Database (print)10
78.8
Complete German Commission E Monographs11
69.7
PDR for Herbal 10
7.6 4.5
5
1.5 0 s er m su n Co
38
re s s ts ca es ist ian rs en ac th ners l u a m sic ud N r t e tio y a h S ti r Ph Ph he prac Ot
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% Respondents
The Review of Natural Products9
Medicines12
66.7
AltMedDex System13
59.1
PDR for Nonprescription Drugs and Dietary Supplements14
56.1
Tyler’s Honest Herbal15
51.5
Natural Medicines Comprehensive Database Web
site16
48.5
Herbs of Choice17
37.9
PDR for Nutritional Supplements18
30.3
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Dietary Supplement Resources
Table 2. Most Commonly Used Dietary Supplement Resources at 66 Drug Information Centers Resource
% Respondents
Natural Medicines Comprehensive Database Web site16
36.4
AltMedDex System13
16.7
The Review of Natural Products9
16.7
Natural Medicines Comprehensive Database
(print)10
15.2
Professional’s Handbook of Complementary and Alternative Medicine19
3.0
Complete German Commission E Monographs11
1.5
Other
1.5
centers. Their survey results indicate that 33.6% of dietary supplement calls received were requests for information rather than reports of ingestion or adverse events. This may in fact indicate that more requestors, health care practitioners as well as the lay public, are using poison control centers than are using drug information centers to obtain information on dietary supplements. Yet another possible explanation for the small number of requests may be that some responding centers accept requests only from institutional affiliates. As half of respondents were primarily affiliated with hospitals, which traditionally have not been greatly involved in direct patient counseling on dietary supplements and often do not allow their use by inpatients, this explanation appears valid. However, we found no correlation between centers’ institutional affiliation and number of dietary supplement information requests. Additionally, as clinical practitioners recognize the increasing portion of their time devoted to discussing patients’ use of dietary supplements,21 one would anticipate seeing an increase in the use of drug information centers as a resource for answering questions about these products. Finally, as mentioned above, many consumers still perceive dietary supplements as natural and safe and, therefore, are not seeking “drug-like” information about them. This patient perception, along with the low rate of usage disclosure to prescribers, may affect the number of requests for supplement information being directed to centers. While the number of information requests specific to dietary supplements represents, in general, a small percentage of the total calls received, drug information centers are, in fact, receiving a significant number of requests about these products. To respond, standard high-quality resources need to be available. Our results indicate that the number of dietary supplement resources held by drug information centers varies greatly, with seven references being held by more than one half of the centers. This variance may be explained, in part, by the limited number of publications22–24 evaluating the quality of dietary supplement references and the lack of a well-recognized gold standard. While no one resource is recognized as the standard, some recommendations have been
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made as to what resources should be considered essential for drug information centers25 as well as for pharmacists in general.22,26 Interestingly, the commonly held resources identified by our survey did not closely match any of the recommendation lists. This mismatch may reflect poor distribution of these recommendations24,26 or the relative newness of some recommendations at the time this survey was conducted.22 It may also reflect the lack of recognition of one particular organization or body as making “official” recommendations. One particular point worth noting is that publication dates of popular dietary supplement information resources varied considerably. Some of the most common resources were not the most recent. The two most commonly reported resources were fairly timely: The print version of Natural Medicine Comprehensive Database10 is updated annually, and portions of The Review of Natural Products9 are updated monthly. However, the third most common resource, The Complete German Commission E Monographs,11 was published in 1998 and is a translation of an earlier work. The timeliness of these resources is important, as information in this field is changing rapidly. Additionally, the resources most commonly used were not those most commonly held. Common use may more accurately reflect ease of use than a critical evaluation of the resource’s quality. Also, the two most commonly used resources were both available in electronic formats, possibly indicating that the ability to easily search by a variety of common names, as well as by some of the most popular brand-name formulations, may be important in a drug information setting. Resources available in electronic formats may also be preferred because their content is updated more frequently than that of print texts. Despite the variety of resources used by respondents, the vast majority of responding centers reported that their resources enabled them to respond to information requests. The level of confidence was not significantly correlated with additional training regarding dietary supplements. This finding conflicts with the intuitive expectation that additional training would increase practitioners’ confidence in their center’s ability to respond to requests for information about supplements. Perhaps specialized training in dietary supplements may instead serve to heighten practitioners’ awareness of the limitations of their knowledge in this area and the limitations of the information available. A variety of factors could affect respondents’ general confidence in their ability to respond to dietary supplement information requests. One factor could be that most dietary supplement information requests came from consumers and, therefore, may have been less technical and complicated than those coming from health care practitioners. A second factor could be the relative lack of training on these topics received by other health care professionals. Nonetheless, drug information center personnel in general believe they are equipped to respond adequately to questions concerning these products.
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Dietary Supplement Resources
References
Limitations This survey was subject to several limitations. The inclusion criteria (being listed in the 2002 Red Book8) would have excluded other established drug information centers that were listed only in other directories as well as centers that opened after the publication of that reference. We chose the Red Book in order to have complete contact information for a representative sample of drug information centers nationwide. Another limitation is that the data were self-reported. This can be a particular problem when collecting numerical data, as we did when asking responders to estimate the numbers of drug information and dietary supplement information requests they received. However, the inclusion of ranges for some responses should have minimized the impact of self-reporting. The resource list provided in the survey might not have included some resources available in responding centers. We included a free response option to minimize the impact of this limitation. However, none of the specific responses to this option were repeated frequently enough to rank among the most commonly used sources. Respondents’ interpretation of their centers’ ability to respond to dietary supplement questions may have been limited by our decision not to attempt to determine the correctness or completeness of responses provided. Centers may not have used the same definition of “response,” and this could have had an impact on the category into which they ranked themselves. For example, a center may rate itself as “always able to respond” with responses that may be variations of “there is not enough information to answer the request.”
Conclusion The resources available at and used by drug information centers to address dietary supplement information requests differed greatly. Despite this, respondents generally felt confident in their center’s ability to respond to these requests. The number of dietary information supplement requests received by centers was not overwhelmingly large. Nonetheless, the consistency of such requests across all centers indicates the need for further study in this area to better understand the proportion, nature, and handling of dietary supplement information requests in the context of drug information services.
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1. Eisenberg DM, Davis RB, Ettner SL, et al. Trends in alternative medicine use in the United States, 1990–1997: results of a follow-up national survey. JAMA. 1998;280:1569−75. 2. Kaufman DW, Kelly JP, Rosenberg L, et al. Recent patterns of medication use in the ambulatory adult population of the United States: the Slone survey. JAMA. 2002;287:337−44. 3. Clauson KA, McQueen CE, Shields KM, Bryant PJ. Knowledge and attitudes of pharmacists in a Midwestern state regarding natural products. Am J Pharm Educ [journal online]. 2003;64(2): Article 41. 4. Rosenberg JM, Fuentes RJ, Starr CH, et al. Pharmacist-operated drug information centers in the United States. Am J Health Syst Pharm. 1995;52:991−6. 5. Dombrowski SR, Visconti JA. National audit of drug information centers. Am J Hosp Pharm. 1985;42:819−26. 6. Matuszewski KA, Windisch PA. Drug information activities in academic health centers: a 1996 survey. Drug Inf J. 1998;32:539−46. 7. Shannon ME, Malecha SE, Cha AJ, Moody ML. Evaluation and critical appraisal of a random sample of drug information practice in United States academic and industry medical information centers. Drug Inf J. 2000;34:1133−8. 8. Cohen HE, ed. 2002 Red book. Montvale, N.J.: Thompson Medical Economics Publishers; 2002. 9. DerMarderosian A, Beutler JA, eds. The review of natural products. St. Louis, Mo.: Facts and Comparisons; 2002. 10. Jellin JM, ed. Natural medicines comprehensive database. Stockton, Calif.: Therapeutic Research Faculty; 2002. 11. Blumenthal M, ed. The complete German Commission E monographs. Austin, Tex.: American Botanical Council; 1998. 12. Fleming T, ed. PDR for herbal medicines. 2nd ed. Montvale, N.J.: Thompson Medical Economics; 2000. 13. AltMedDex system. Greenwood Village, Colo.: Micromedex; 2002. 14. Walsh P. PDR for nonprescription drugs and dietary supplements. Montvale, N.J.: Thompson Medical Economics; 2002. 15. Foster S, Tyler VE. Tyler’s honest herbal. 4th ed. Binghampton, N.Y.: Hawthorne Herbal Press; 1999. 16. Natural medicines comprehensive database Web site. Available at: www.naturaldatabase.com. Accessed October 6, 2003. 17. Robbers JE, Tyler VE. Herbs of choice. Binghampton, N.Y.: Hawthorne Herbal Press; 1999. 18. Fleming T, ed. PDR for nutritional supplements. Montvale, N.J.: Thompson Medical Economics; 2001. 19. Fetrow CW, Avila JR, eds. Professional’s handbook of complementary and alternative medicines. 2nd ed. Springhouse, Pa.: Springhouse; 2001. 20. Palmer ME, Haller C, McKinney PE, et al. Adverse events associated with dietary supplements: an observational study. Lancet. 2003;361(9352):101−6. 21. Knapp KK, Blalock SJ, Black BL. ASHP survey of ambulatory care responsibilities of pharmacists in managed care and integrated health systems—2001. Am J Health Syst Pharm. 2001;58:2151−61. 22. Chambliss WG, Hufford CD, Flagg ML, Glisson JK. Assessment of the quality of reference books on botanical dietary supplements. J Am Pharm Assoc. 2002;42:723−34. 23. Walker JB. Evaluation of the ability of seven herbal resources to answer questions about herbal products asked in drug information centers. Pharmacotherapy. 2002;22:1611−5. 24. Sweet BV, Gay WE, Leady MA, Stumpf JL. Usefulness of herbal and dietary supplement references. Ann Pharmacother. 2003;37:494−9. 25. McQueen CE, Clauson KA, Bryant PJ. Appropriate resources for addressing the most common categories of natural product information requests. Paper presented at: American Society of Health-System Pharmacists Midyear Clinical Meeting; December 3−7, 2000; Las Vegas, Nev. 26. Malone PM, Kier KL, Mosdell KW, Stanovich J. Drug information resources In: Drug information: a guide for pharmacists. 2nd ed. New York, NY: McGraw-Hill Company; 2001.
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Vol. 44, No. 1
National Survey of Dietary Supplement Resources at Drug Information Centers Kelly M. Shields, Cydney E. McQueen, and Patrick J. Bryant
Received April 21, 2003, and in revised form June 19, 2003. Accepted for publication August 4, 2003.
ABSTRACT
Participants: 116 drug information centers.
Kelly M. Shields, PharmD, is Assistant Clinical Professor and Assistant Director, Drug Information Center, Raabe College of Pharmacy, Ohio Northern University, Ada. At the time this research was conducted, Shields was natural product information and research fellow with the University of Missouri Kansas City Drug Information Center, Kansas City, Mo. Cydney E. McQueen, PharmD, is Assistant Director, Drug Information Center, and Clinical Assistant Professor; Patrick J. Bryant, PharmD, is Director, Drug Information Center, and Clinical Associate Professor, School of Pharmacy, University of Missouri–Kansas City.
Interventions: Mail survey that collected information on the use of drug information centers for dietary supplement information requests and the dietary supplement-specific resources available at and used in these centers.
Correspondence: Cydney E. McQueen, PharmD, Drug Information Center, University of Missouri–Kansas City, 2411 Holmes, Suite MG-200, Kansas City, MO. 64108. Fax: 816-235-5491. E-mail: [email protected].
Main Outcomes Measures: Survey responses, evaluated using descriptive statistics.
Disclosure: The authors declare no conflicts of interest or financial interests in any product or service mentioned in this article, including grants, employment, gifts, stock holdings, or honoraria. Shields and McQueen have served as content reviewers for Natural Medicines Comprehensive Database.
Objective: To assess the resources drug information centers are currently using to respond to dietary supplement information requests and to determine the frequency with which drug information centers are used as sources of information on dietary supplements. Design: Cross-sectional survey. Setting: United States.
Results: Drug information centers received a relatively small number of requests for information related to dietary supplements, and most such requests came from consumers. The centers had a number of resources available to assist in responding to those requests, with Facts and Comparisons’ The Review of Natural Products and the print version of Natural Medicines Comprehensive Database being the resources most often at hand. The majority of respondents believed their centers were “usually able” to respond to the requests received.
Presented previously at the American Pharmaceutical Association Annual Meeting, March 31, 2003, New Orleans, La.
Conclusion: Drug information centers are often overlooked as sources of information about dietary supplements; however, centers have resources that are, by self-assessment, sufficient to respond to dietary supplement information requests. Great variation exists among centers in the resources available to address requests, with just two resources, the Review of Natural Products and the print version of Natural Medicines Comprehensive Database, available to more than three-fourths of the respondents. Keywords: Dietary supplements, drug information centers, information sources, natural products. J Am Pharm Assoc. 2004;44:36–40.
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Vol. 44, No. 1
Dietary Supplement Resources
T
he increased use of dietary supplements over the past decade in all patient populations has been well documented.1,2 Yet, for reasons that remain unclear, the majority of patients are not informing health care practitioners of their use of these products.1 Possibly, patients perceive dietary supplements as “natural” and therefore safe, or they may believe that health care practitioners have negative attitudes toward or are not well informed about dietary supplements. Even though the majority of patients are not discussing supplement use with practitioners, due to the increasing volume of use, practitioners are nonetheless likely receiving more requests for information about dietary supplements. Drug information centers would, therefore, likely see corresponding increases in questions on supplements. This change is difficult to assess globally because no studies evaluating the number of dietary supplement information requests centers receive from health care practitioners have been reported to date, and, therefore, baseline numbers are not available for comparison. Results of one recent survey indicate that fewer than 10% of pharmacists contact drug information centers when they have questions about dietary supplements.3 Pharmacists may be hesitant to rely on these resources for information on supplements to the same extent that they do for information about medications because they perceive that centers lack the resources, expertise, or desire to provide information regarding dietary supplements. While previous studies have assessed trends in the growth of drug information centers and looked at the services they pro-
AT A GLANCE Synopsis: Despite the huge increase in use of dietary supplements by the American public over the past decade, drug information centers are receiving relatively small numbers of requests for information about these products. According to the results of this national survey of drug information centers, consumers are more likely than health professionals to ask questions about dietary supplements. The centers use a variety of reference materials to respond to such queries, with printed materials being the most commonly available source of information. However, centers are more likely to use Web-based references, despite the wider availability of printed materials. Analysis: Other published studies show that poison control centers receive a fair number of calls about adverse effects of dietary supplements, but consumers and health professionals do not often turn to drug information centers for information about these products. Given the wealth of knowledge and expertise available in drug information centers, there should be greater use of this resource for information on herbal products, vitamins and minerals, and other dietary supplements.
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vide,4–7 few have assessed the resources of these centers,4,5 and none has evaluated which specific dietary supplement resources are held by drug information centers.
Objectives We undertook this survey to assess the resources drug information centers are currently using to respond to dietary supplement information requests and to determine the frequency with which drug information centers are used as sources of information on dietary supplements.
Methods We sent notification letters to the directors of the 116 drug information centers identified in the 2002 Red Book,8 informing them that a survey would follow 1 week later. The survey was then sent to the same centers along with a cover letter explaining the purpose of the survey and requesting it be returned via fax or in an enclosed self-addressed, stamped envelope. Surveys were coded so that a second survey could be sent to nonresponders. The survey period was November 2002 through January 2003. Two weeks after the first mailing, we sent a second copy of the same survey instrument and completion instructions. Surveys returned within 30 days after the second mailing were included in the results. The survey instrument gathered descriptive data, including institutional information, dietary supplement information sources the center currently used, dietary supplement resources available in the center, and a self-evaluation of the center’s ability to respond to requests. If respondents selected multiple responses to the same question or returned two surveys, only the first response or survey was used. We made no attempts to contact respondents to clarify responses or obtain incomplete or missing data. Survey data were tabulated using SPSS version 11.0 (Chicago, Ill.). Statistical tests included mean, average, and χ2. The project was approved by the University of Missouri− Kansas City Social Sciences Institutional Review Board.
Results We received 49 responses to the initial mailing. One survey was returned due to an incorrect address. We received 18 additional responses to the second mailing. Thus, a total of 67 responses were received, for a response rate of 57.8%. Because one survey was returned without any data recorded, the number of usable surveys was 66 (56.9%). Results from eight surveys received after the 30day deadline were not included in the data analysis. Responding centers were most often affiliated with a hospital (50.0%), followed by college of pharmacy (28.8%) and medical
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center (15.2%). The number of full-time drug information specialists on staff at responding centers ranged from 1 to 4, with 51.5% having only 1 full-time drug information specialist. Most of the responding centers—65.2%—reported no additional training for drug information specialists in the area of dietary supplements, while 22.7% indicated that “dietary supplement training” consisted of a continuing education program on the topic. The average number of drug information requests received monthly ranged from 51 to 100. Respondents indicated that most drug information requests came from pharmacists (42.4%) and physicians (31.8%). Dietary supplement requests, on average, accounted for a mean ± standard deviation (SD) of 7.8% ± 6.4% (range, 0.5%−25.0%) of all requests. A positive correlation was found between the number of drug information requests and the number of dietary supplement requests, indicating that, proportionally, the busiest centers received the most requests relating to dietary supplements. Most dietary supplement information requests came from consumers (30.3%), followed closely by nurses and other health care practitioners (see Figure 1). Requests from pharmacists and physicians lagged far behind, at 7.6% and 4.5%, respectively. Of the 30 resources listed in the survey, the most commonly held dietary supplement resources were Facts and Comparisons’ The Review of Natural Products9 and the print version of Natural Medicines Comprehensive Database.10 Seven resources were held by more than one half of the respondents. The 10 most commonly reported resources are listed in Table 1. The other resources were held by fewer than 10% of respondents. Respondents also listed the dietary supplement resources most commonly used (as opposed to held) in their practice setting. The resource most commonly used was the online version of Natural Medicines Comprehensive Database16 (36.4%), followed by AltMedDex System13 (16.7%) (see Table 2). Most respondents indicated they are “usually able to respond” Figure 1. Percentages of Queries Received from Various Groups About Dietary Supplements at 66 Drug Information Centers 35 30
30.3
Discussion It appears that many health care practitioners are not making use of the resources available at drug information centers when responding to dietary supplement information requests. The very small number of dietary supplement requests (7.6%), as opposed to general drug information requests (42.4%), the centers reported receiving from pharmacists could be explained to some extent if pharmacists were directly referring patients to these centers. If this were true, then the large number of requests from consumers would be expected. However, based on handwritten notes on survey responses, some drug information centers do not accept requests directly from consumers; therefore, this reason cannot fully explain the unexpectedly high consumer usage and low pharmacist usage of the centers as resources for information on dietary supplements. Interestingly, the portion of dietary supplement information requests received from all requesters was small compared with the number of general drug information requests received. Several factors could explain this difference. Possibly, requesters did not believe drug information centers would have sufficient resources to respond to their requests. Our results should help alleviate this concern. Another explanation may be that questions about dietary supplements are being directed to poison control centers rather than drug information centers. Palmer et al.20 examined the number of dietary supplement ingestion reports handled by poison control
Table 1. Most Commonly Held Dietary Supplement Information Resources at 66 Drug Information Centers Resource
25.8
25
(63.6%) or “always able to respond” (22.7%) to dietary supplement information requests. The remaining 12.1% were “sometimes able to respond.” We found no statistically significant correlation between centers with personnel having additional dietary supplement training and respondents’ ratings of their ability to respond to dietary supplement information requests (P = .82).
22.7 20 15
78.8
Natural Medicines Comprehensive Database (print)10
78.8
Complete German Commission E Monographs11
69.7
PDR for Herbal 10
7.6 4.5
5
1.5 0 s er m su n Co
38
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% Respondents
The Review of Natural Products9
Medicines12
66.7
AltMedDex System13
59.1
PDR for Nonprescription Drugs and Dietary Supplements14
56.1
Tyler’s Honest Herbal15
51.5
Natural Medicines Comprehensive Database Web
site16
48.5
Herbs of Choice17
37.9
PDR for Nutritional Supplements18
30.3
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Table 2. Most Commonly Used Dietary Supplement Resources at 66 Drug Information Centers Resource
% Respondents
Natural Medicines Comprehensive Database Web site16
36.4
AltMedDex System13
16.7
The Review of Natural Products9
16.7
Natural Medicines Comprehensive Database
(print)10
15.2
Professional’s Handbook of Complementary and Alternative Medicine19
3.0
Complete German Commission E Monographs11
1.5
Other
1.5
centers. Their survey results indicate that 33.6% of dietary supplement calls received were requests for information rather than reports of ingestion or adverse events. This may in fact indicate that more requestors, health care practitioners as well as the lay public, are using poison control centers than are using drug information centers to obtain information on dietary supplements. Yet another possible explanation for the small number of requests may be that some responding centers accept requests only from institutional affiliates. As half of respondents were primarily affiliated with hospitals, which traditionally have not been greatly involved in direct patient counseling on dietary supplements and often do not allow their use by inpatients, this explanation appears valid. However, we found no correlation between centers’ institutional affiliation and number of dietary supplement information requests. Additionally, as clinical practitioners recognize the increasing portion of their time devoted to discussing patients’ use of dietary supplements,21 one would anticipate seeing an increase in the use of drug information centers as a resource for answering questions about these products. Finally, as mentioned above, many consumers still perceive dietary supplements as natural and safe and, therefore, are not seeking “drug-like” information about them. This patient perception, along with the low rate of usage disclosure to prescribers, may affect the number of requests for supplement information being directed to centers. While the number of information requests specific to dietary supplements represents, in general, a small percentage of the total calls received, drug information centers are, in fact, receiving a significant number of requests about these products. To respond, standard high-quality resources need to be available. Our results indicate that the number of dietary supplement resources held by drug information centers varies greatly, with seven references being held by more than one half of the centers. This variance may be explained, in part, by the limited number of publications22–24 evaluating the quality of dietary supplement references and the lack of a well-recognized gold standard. While no one resource is recognized as the standard, some recommendations have been
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made as to what resources should be considered essential for drug information centers25 as well as for pharmacists in general.22,26 Interestingly, the commonly held resources identified by our survey did not closely match any of the recommendation lists. This mismatch may reflect poor distribution of these recommendations24,26 or the relative newness of some recommendations at the time this survey was conducted.22 It may also reflect the lack of recognition of one particular organization or body as making “official” recommendations. One particular point worth noting is that publication dates of popular dietary supplement information resources varied considerably. Some of the most common resources were not the most recent. The two most commonly reported resources were fairly timely: The print version of Natural Medicine Comprehensive Database10 is updated annually, and portions of The Review of Natural Products9 are updated monthly. However, the third most common resource, The Complete German Commission E Monographs,11 was published in 1998 and is a translation of an earlier work. The timeliness of these resources is important, as information in this field is changing rapidly. Additionally, the resources most commonly used were not those most commonly held. Common use may more accurately reflect ease of use than a critical evaluation of the resource’s quality. Also, the two most commonly used resources were both available in electronic formats, possibly indicating that the ability to easily search by a variety of common names, as well as by some of the most popular brand-name formulations, may be important in a drug information setting. Resources available in electronic formats may also be preferred because their content is updated more frequently than that of print texts. Despite the variety of resources used by respondents, the vast majority of responding centers reported that their resources enabled them to respond to information requests. The level of confidence was not significantly correlated with additional training regarding dietary supplements. This finding conflicts with the intuitive expectation that additional training would increase practitioners’ confidence in their center’s ability to respond to requests for information about supplements. Perhaps specialized training in dietary supplements may instead serve to heighten practitioners’ awareness of the limitations of their knowledge in this area and the limitations of the information available. A variety of factors could affect respondents’ general confidence in their ability to respond to dietary supplement information requests. One factor could be that most dietary supplement information requests came from consumers and, therefore, may have been less technical and complicated than those coming from health care practitioners. A second factor could be the relative lack of training on these topics received by other health care professionals. Nonetheless, drug information center personnel in general believe they are equipped to respond adequately to questions concerning these products.
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Dietary Supplement Resources
References
Limitations This survey was subject to several limitations. The inclusion criteria (being listed in the 2002 Red Book8) would have excluded other established drug information centers that were listed only in other directories as well as centers that opened after the publication of that reference. We chose the Red Book in order to have complete contact information for a representative sample of drug information centers nationwide. Another limitation is that the data were self-reported. This can be a particular problem when collecting numerical data, as we did when asking responders to estimate the numbers of drug information and dietary supplement information requests they received. However, the inclusion of ranges for some responses should have minimized the impact of self-reporting. The resource list provided in the survey might not have included some resources available in responding centers. We included a free response option to minimize the impact of this limitation. However, none of the specific responses to this option were repeated frequently enough to rank among the most commonly used sources. Respondents’ interpretation of their centers’ ability to respond to dietary supplement questions may have been limited by our decision not to attempt to determine the correctness or completeness of responses provided. Centers may not have used the same definition of “response,” and this could have had an impact on the category into which they ranked themselves. For example, a center may rate itself as “always able to respond” with responses that may be variations of “there is not enough information to answer the request.”
Conclusion The resources available at and used by drug information centers to address dietary supplement information requests differed greatly. Despite this, respondents generally felt confident in their center’s ability to respond to these requests. The number of dietary information supplement requests received by centers was not overwhelmingly large. Nonetheless, the consistency of such requests across all centers indicates the need for further study in this area to better understand the proportion, nature, and handling of dietary supplement information requests in the context of drug information services.
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1. Eisenberg DM, Davis RB, Ettner SL, et al. Trends in alternative medicine use in the United States, 1990–1997: results of a follow-up national survey. JAMA. 1998;280:1569−75. 2. Kaufman DW, Kelly JP, Rosenberg L, et al. Recent patterns of medication use in the ambulatory adult population of the United States: the Slone survey. JAMA. 2002;287:337−44. 3. Clauson KA, McQueen CE, Shields KM, Bryant PJ. Knowledge and attitudes of pharmacists in a Midwestern state regarding natural products. Am J Pharm Educ [journal online]. 2003;64(2): Article 41. 4. Rosenberg JM, Fuentes RJ, Starr CH, et al. Pharmacist-operated drug information centers in the United States. Am J Health Syst Pharm. 1995;52:991−6. 5. Dombrowski SR, Visconti JA. National audit of drug information centers. Am J Hosp Pharm. 1985;42:819−26. 6. Matuszewski KA, Windisch PA. Drug information activities in academic health centers: a 1996 survey. Drug Inf J. 1998;32:539−46. 7. Shannon ME, Malecha SE, Cha AJ, Moody ML. Evaluation and critical appraisal of a random sample of drug information practice in United States academic and industry medical information centers. Drug Inf J. 2000;34:1133−8. 8. Cohen HE, ed. 2002 Red book. Montvale, N.J.: Thompson Medical Economics Publishers; 2002. 9. DerMarderosian A, Beutler JA, eds. The review of natural products. St. Louis, Mo.: Facts and Comparisons; 2002. 10. Jellin JM, ed. Natural medicines comprehensive database. Stockton, Calif.: Therapeutic Research Faculty; 2002. 11. Blumenthal M, ed. The complete German Commission E monographs. Austin, Tex.: American Botanical Council; 1998. 12. Fleming T, ed. PDR for herbal medicines. 2nd ed. Montvale, N.J.: Thompson Medical Economics; 2000. 13. AltMedDex system. Greenwood Village, Colo.: Micromedex; 2002. 14. Walsh P. PDR for nonprescription drugs and dietary supplements. Montvale, N.J.: Thompson Medical Economics; 2002. 15. Foster S, Tyler VE. Tyler’s honest herbal. 4th ed. Binghampton, N.Y.: Hawthorne Herbal Press; 1999. 16. Natural medicines comprehensive database Web site. Available at: www.naturaldatabase.com. Accessed October 6, 2003. 17. Robbers JE, Tyler VE. Herbs of choice. Binghampton, N.Y.: Hawthorne Herbal Press; 1999. 18. Fleming T, ed. PDR for nutritional supplements. Montvale, N.J.: Thompson Medical Economics; 2001. 19. Fetrow CW, Avila JR, eds. Professional’s handbook of complementary and alternative medicines. 2nd ed. Springhouse, Pa.: Springhouse; 2001. 20. Palmer ME, Haller C, McKinney PE, et al. Adverse events associated with dietary supplements: an observational study. Lancet. 2003;361(9352):101−6. 21. Knapp KK, Blalock SJ, Black BL. ASHP survey of ambulatory care responsibilities of pharmacists in managed care and integrated health systems—2001. Am J Health Syst Pharm. 2001;58:2151−61. 22. Chambliss WG, Hufford CD, Flagg ML, Glisson JK. Assessment of the quality of reference books on botanical dietary supplements. J Am Pharm Assoc. 2002;42:723−34. 23. Walker JB. Evaluation of the ability of seven herbal resources to answer questions about herbal products asked in drug information centers. Pharmacotherapy. 2002;22:1611−5. 24. Sweet BV, Gay WE, Leady MA, Stumpf JL. Usefulness of herbal and dietary supplement references. Ann Pharmacother. 2003;37:494−9. 25. McQueen CE, Clauson KA, Bryant PJ. Appropriate resources for addressing the most common categories of natural product information requests. Paper presented at: American Society of Health-System Pharmacists Midyear Clinical Meeting; December 3−7, 2000; Las Vegas, Nev. 26. Malone PM, Kier KL, Mosdell KW, Stanovich J. Drug information resources In: Drug information: a guide for pharmacists. 2nd ed. New York, NY: McGraw-Hill Company; 2001.
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