REFEREED ARTICLE Consumer Involvement in Nonprescription Medicine Purchase Decisions By Prasanna Gore, Suresh Madhavan, Gordon McClung, and David Riley A s self-medication with nonprescription drugs becomes increasingly popular and important in this era of escalating health care costs and growing consumer sophistication, the degree of consumer involvement in the purchase decision becomes an important factor High involvement suggests active informationseeking behavior and, therefore, a greater likelihood of appropriate nonprescription drug use The authors assess consumer involvement in nonprescription medicine purchase decisions and the use of expert sources of information 16 Summer 1994—Vol 14, No S elf-medication with nonprescription medicines is the most cost-effective form of health care, and it represents one major strategy for containing health care costs In 1993, U.S consumers spent $13.3 billion on nonprescription medicines, according to the Nonprescription Drug Manufacturers Association, and the category continues to experience steady growth Several reasons have been cited in the trade press for the growing popularity of nonprescription medicines, including consumer convenience and savings in time and money from not having to visit a physician as well as various societal trends such as the aging of the population, growing consumer sophistication, the shift in drug products from prescription to nonprescription status, and the escalating cost of health care Nonprescription medicines account for only 2^; of every health care dollar spent, according to the Health Care Financing Administration's 1993 industry statistics, yet have proven to be the most costeffective form of health care Consumers saved $23.8 billion in 1987 because of the availability of nonprescription medicines, Charles Kline reported during a 1988 meeting of The Proprietary Association These savings resulted from not having to pay physicians' fees, not having to travel to and from the physician's office and lose work-hours, and not having to pay for costly prescription drugs Although these are the most current statistics available, the savings may prove to be even greater once the industry releases an update While self-medication with nonprescription medicines for the treatment of minor ailments is a desirable trend, it also has of inappropriate consumer use of nonprescription medicines, primarily involving misinterpretion and misuse Some consumers are unable to interpret label information correctly and others delay medical treatment for a more serious underlying disease, overdose, or use nonprescription drugs chronically, which may lead to physical damage or addiction Nonprescription drugs also are known to interfere with laboratory test values, cause adverse interactions with prescription drugs, and sometimes even render some prescription drugs ineffective, according to P.P Lamy in a 1982 Joiir^wl of the American Geriatrics Society article, "Over-the-Counter Medication: The Drug Interactions We Overlook." Adverse drug interactions are particularly common in the elderly who are more likely to be undergoing treatment with prescription drugs for one or more ailments while also self-medicating with nonprescription medicines, Lamy pointed out that the elderly also are more vulnerable to the harmful effects of nonprescription medicines because they generally not discuss their nonprescription medicine use with either their physician or their pharmacist Thus, the improper use of nonprescription medicines can be harmful and their purpose of providing cost-effective health care can be defeated if they are not used in a safe and effective manner Given the wide range of mishaps possible with nonprescription medicines and the estimated 300,000 nonprescription products Holt and Hall reported to be on the market in 1990, it is not surprising that consumers turn to a variety of information sources for help in solving problems relating to nonprescription medicine purchase and use To decide which nonprescription medicine is most suitable for their condition, consumers generally rely on the following available information sources: Nonprescription medicines account for only 20 of every health care dollar spent its drawbacks In the Handbook of Nonprescription Drugs, Gary Holt and Edwin Hall maintain that a large number of consumers lack the ability to self-diagnose self-limiting conditions accurately Researchers and the trade press have reported cases EXECUTIVE HIGHLIGHTS • Self-medication with nonprescription medicines for the treatment of minor ailments is a desirable trend that can help keep health care costs down • Involvement in nonprescripfion medicine purchases increases the likelihood of consumers seeking advice and information from expert sources such as physicians, pharmacists, and nurses • Seeking out expert advice not only helps consumers make better purchase decisions, but also ensures the safe and effective use of nonprescription medicines This is especially important in the case of elderly consumers who often take multiple medications • By determining the degree of consumer involvement, health care marketers can target appropriate communications to segments that would benefit from greater involvement in such purchase decisions • Marketer-dominated sources such as TV, radio, and print ads as well as point-of-sale information from store displays, product labels, etc • General media sources such as reference books, consumer reports, buying guides, etc • "People" sources such as experts (pharmacists, physicians, nurses, etc.) and laypersons (family members, friends, and colleagues) Of these sources, the marketer-dominated ones primarily build awareness and interest and sometimes educate consumers about drug products Product labels and general media sources provide detailed information about the various products However, when a large number of choices are available, the marketer-dominated or general media sources rarely help consumers make an informed purchase decision In fact, these sources can create information overload and confusion in the minds of consumers The marketer-dominated sources often not provide sufficient and easy-to-understand information about drug interactions, contra-indications, side-effects, and other such important information relevant to the safe and effective use of nonprescription medicines Product labels and general media sources, though providing detailed Information, may provide it in a manner diffiJournal of Health Care Marketing 17 cult for consumers to understand EXHIBIT or interpret Numerous choices also can make it very difficult for a Mean Scores, Factor Scores, and Reliability Statistics consumer to determine which [tern mean ± Item-total Factor Alpha if nonprescription medicine is most Scales (N=435) correlation loading item deleted S.D suitable for his or her specific conInvolvement 4.20 ± 0.50 0.34* dition and symptoms This is when consumers typiTake long time to decide before cally seek more information and 0.7604 3,57 2: 1.71 0.47 0.6344 buying nonprescription medicines help, which leads them to the Get as much information as posexpert or lay "people" sources of sible before buying a nonprescription information 4,42 ±1.52 0.61 0.7785 0.7326 medicine People sources can help a conInterested in reading information sumer understand product-relatabout how nonprescription 0.59 0.7534 0.7374 4.69 ± 1.49 medicines work ed information in layperson terms, evaluate and individual; \ Compared product characteristics ize pertinent information, and among brands of nonprescription 4.35 ± 1.63 0.61 0.7666 0.7311 medicines also provide a frame of reference for decision making Expert Perceive product characteristics sources help consumers underamong brands of nonprescription 0.5976 0.7641 3.39 ± 1.74 0.45 medicines stand, interpret, and individualize medication-related informaWould be interested in reading a tion and also are able to recomConsumer Reports article about a 0.7692 4.63 ± 1.58 0.42 0.5756 needed nonprescription medicine mend a medicine of choice Lay sources may help by sharing Have a most-preferred brand for their illness or medicine use the different kinds of commonly 0.7795 4.35 ± 1.65 0.37 0.5047 used nonprescription medicines experience and knowledge, Scale mean == 29.44 thereby providing a frame of refScale s.d = 7.48 erence for decision making for Cronbach's alpha = 0.7849 nonprescription medicine pur* Value indicates mean of inter-item correlations foi- liio scale chase and use However, both the expert and lay people sources are useful only if consumers are decision making was classified by James Engel and Roger sufficiently involved in their nonprescription medicine purchasBlackweil in their 1982 Consumer Behavior text as being high es and actively seek help in the face of uncertainty or problems or low involvement-type in nature In a high-involvement decision, the consumer goes through an extended problemsolving process: recognizing the problem, actively searching for information, evaluating the alternatives, and then making the purchase decision Also, involvement in a purchase deciThe information processing theory in consumer behavior literasion leads the consumer to "search for ture suggests that the consumer is an intellimore information and spend more gent, ratior\al, problem-solver who actively time searching for the right selection," seeks and uses information to evaluate the according to Keith Clarke and Russell various alternatives or choices Researchers Belk in Advances in Consumer Research have documented this information-seeking and problem-solving behavior in the past, In a low-involvement purchase decibut also found evidence that the extent of sion, because the purchase does not information search, problem solving, and have much significance to the conevaluation of altematives in the consumer's sumer, he or she does not extensively decision-making process may vary with the search for information, and rarely evalsignificance or degree of importance of the uates alternatives or choices before decision to the consumer making the purchase decision, said Engel and Blackweil A consumer makes many decisions Even though nonprescription medieach day, and only some of them are sigcines are safe and effective, therapeutic nificant or important, said Judith outcomes may not be achieved or Zaichkowsky in her 1985 Journal of mishaps may occur in many cases Consumer Research article, "Measuring because of (1) lack of information, (2) information not being the Involvement Construct." Even though complex and expenunderstood or being misinterpreted, or (3) just too much inforsive purchases are likely to involve the consumer, frequent and mation causing confusion The study of consumer involvement less expensive purchases seldom involve the consumer has significance because consumers' information search during Depending on the degree of involvement in a purchase nonprescription medicine purchases is a function of their decision, the extent of information-seeking behavior, and the involvement in the purchase decision degree of awareness about purchase alternatives, consumer Consumer Involvement The consumer is an intelligent, rational, problem-solver who actively seeks and uses information to evaluate the various alternatives 18 Summer 1994—Vol 14, No Active information-seeking behavior—such as consulting people sources of information when labeled information is not clear or when conditions are present that complicate safe and effective medicine use—is more likely among consumers who are involved in their nonprescription medicine purchases Also, the greater the involvement, the greater the likelihood that consumers will seek expert people sources of information instead of lay people sources of information The extent of involvement may not only dictate the search for information, but also determine to what extent consumers are aware of the proper use of nonprescription medicines, Thus, consumers who are highly involved are more likely to search for information and also understand the importance of safe and effective use of nonprescription medicines Study Goal and Questions The overall goal of this exploratory study was to determine the extent of consumer involvement in nonprescription medicine purchase decisions To accomplish this, we asked the following research questions: • Are consumers' nonprescription medicine purchases characterized by high or low involvement decision-making behavior? • Does consumer involvement in nonprescription medicine purchase decisions vary by age, gender, marital status, education, income, and buying role in the family? • Does consumer involvement differ when compared on the basis of the following nonprescription purchase and use characteristics: frequency of purchase and use, amount spent on nonprescription medicine purchases in a month, most frequent place of purchase of nonprescription medicines, number of therapeutic types of nonprescription medicines stocked at home, and number of sources of information normally consulted? • To what extent is the degree of involvement in nonprescription medicine purchases related to the consultations with, and acceptance of recommendations from, expert and layperson sources of information? • Are consumers who seek information predominantly from expert people sources more involved in nonprescription medicine purchases than consumers who seek information predominantly from layperson sources? Methodology A total of 3,000 randomly selected consumer households in West Virginia, Pennsylvania, Ohio, Maryland, Virginia, and Kentucky were extracted from the National Consumer Index database to be surveyed via a mail questionnaire These consumers were asked to return the completed questionnaires via business reply mail; after two weeks elapsed, a second mailing was sent to those who did not respond to the first Measuring Consumer Involvement Zaichkowsky proposed that consumers who demonstrate a high level of involvement in a purchase decision seek more information about the product, take a longer time to make a decision, evaluate product alternatives, and perceive brand differences We developed a scale to measure consumer involvement specific to nonprescription medicine purchases The scale consisted of seven items representing the various theoretical propositions about the involvement construct: search for information, evaluation of product alternatives, and perception of differences among the various brands We modified five of Zaichkowsky's items to measure involvement in the nonprescription medicine purchase context and developed the other two items to further reflect the information-search characteristic' of the involvement construct The questionnaire asked respondents to indicate the extent of their agreement or disagreement with each of the seven items by rating each item on a 7-point Likert-type scale, in which = "strongly disagree" and = "strongly agree." An aggregate involvement score was calculated for each respondent by summing up the scores on the seven items The questionnaire obtained respondents' demographic and nonprescription medicine purchase and use characteristics using categorical questions as well as a few open-ended questions, which, for the purpose of some analysis, were later grouped into categories Results We received 458 usable responses from the two mailings, for a net response rate of 15.2% Because of the low response rate, we decided to use the extrapolation approach to nonresponse analysis, which is based on the assumption that people who respond late are more like nonrespondents Therefore, we classified the first 100 consumers who responded after the first mailing of the study questionnaire early respondents and the last 100 consumers who responded to the second mailing as late respondents The early and late respondents were compared on demographic and nonprescription medicine purchase characteristics and no significant differences were found between the two groups on any of the demographic and nonprescription medicine purchase and use characteristics Also, the groups were not significantly different on the involvement score Overall, the results of the noriresponse analysis did not indicate a need for any adjustment or transformation of the data However, because die results of this study represent only 15,2% of the respondents surveyed, we advise extreme caution and conservatism in interpreting the results of the study and extrapolating the findings to the larger population Reliability and Validity Assessment Because the items developed for the involvement construct were modified from literature, we tested the involvement scale for internal consistency or reliability (see Exhibit 1) Cronbach's alpha reliability coefficient for the seven-item scale was found to be 78, which is acceptable We assessed construct validity of the involvement scale through factor analysis of the scale items Principal components factor analysis indicated the existence of a single factor with all item loadings greater than 50 Because there was only one preconceptualized construct, the one factor solution suggested good construct validity Furthermore, the loading of all seven items on one factor indicated that the "assumption of a simple linear combination of the scale items was not violated," according to Zaichkowsky, lournal nf Health Carc> EXHIBIT Consumers' Involvement Score by Their Characteristics Characteristic Gender Male Female N Mean SJ) 247 27.49 30.88 7.49 7.14 305 120 30.21 27.50 7.30 7.58 185 Main buyer in the family? Yes No Educational level Up to high school Some college College graduate Postgraduate Annual family income Below $20,000 $20,000-130.000 $30,000-$40,000 $40,000-$50,000 $50,000 ormore llB 94 30.65 - i i 30.81-1- 7.78 7.16 105 27.85-' 7.40 112 28.58 -^ -* 7.19 62 67 64 47 171 32.09 -, 32.20 n 29.50 28.87 28.07 -I-" 6.68 7.44 6.98 7.14 7.35 J Amount spent on nonprescnption medicines in a month $0-$5 $6-$10 $ll-$20 $21 or more Test Statistic t = -4.77 D.F t = -3.41 423 O.DOl* F = 4.22 (3,423) 0.005* F = 6.10 (4,406) 0,000* 430 ^gnificance 0.000* of involvement in nonprescription medicine purchase decisions was found to be inversely related to consumer education and family income The higher the educational level or family income, the lower the involvement in nonprescription medicine purchase decisions Consumer involvement did not differ when comparing marital status, frequency of purchase, frequency of use, and place where nonprescription medicines were purchased However, we noted significant differences when consumer involvement was compared on the basis of average monthly spending on nonprescription medicines The higher the spending level, the greater the involvement in the purchase decision Differences in consumer involvement on the 145 28.19 -|-| 7.77 basis of frequency of 126 28.94 7,53 expert and lay source con112 30.88 -1 6.75 sultations and frequency 33 31.54 -J 8.31 of accepting the recomNOTE: There were no significant differences in consumers* involvement scores when compared on the basis of the following consumer mendations are reported characteristics: marital atatus (p