This study among Norwegian pharmacy customers shows a relatively high public knowledge of antibiotics and antibiotic resistance comparable to studies from Sweden [21, 22], and higher than in many other countries . The higher knowledge scores on antibiotic resistance compared with general knowledge of antibiotics may be due to the increasing focus on antibiotic resistance in media in later years . This could also be seen as a result of the national strategy against antibiotic resistance , including the national information campaign , which may have spurred the media focus.
Similarly to previous studies [21, 22, 27], we identified that people tend to know that antibiotic resistance is a result of inappropriate or unnecessary antibiotic use, and that it makes the antibiotics less effective, but they do not necessarily know what antibiotic resistance or unnecessary use is. For instance, our data show that almost 90% believe that humans can become resistant against antibiotics and many do not differentiate between bacteria and virus, with over 30% saying that antibiotics are effective against viruses, colds or influenza. Some may not know that colds and influenza are all viral infections. Considering the six knowledge statements in common with the Eurobarometer , our study participants would have reached first place for knowing that antibiotics do not kill viruses (76%), but only tenth for correctly dismissing effectiveness against colds and influenza. To mitigate unnecessary use of antibiotics, it would be helpful if patients were aware of this. Our findings are in accordance with an interview study commissioned by the Norwegian Directorate of Health in 2016 (not published) . Focus group interviews conducted among Norwegian parents showed that there is an interest in antibiotic resistance, but the concept is easily misunderstood.
The particularly low score on penicillin being another word for antibiotics is understandable as penicillin was the first marketed antibiotic and a tremendously important medicinal discovery. It is also the most used antibiotic in Norway and the name has become fixed in people’s minds. Although this may seem trivial, it adds unwanted confusion. For instance, patients may say they are “allergic to penicillin”, and so the doctor unnecessarily prescribes a broad-spectrum antibiotic. The statement that antibiotics can be taken together with food may be somewhat ambiguous, as many antibiotics are not noticeably influenced by food intake, thereby leading to uncertainty among the participants. Even for oral penicillin, where food intake inhibits the absorption, avoiding food is less important for optimal effect than administering the doses at regular, frequent time intervals .
Antibiotic knowledge was positively associated with positive beliefs about medications and with increasingly restrictive attitude toward antibiotic use. Our results are in line with previous reports showing that beliefs and attitudes are important for knowledge of medications , including antibiotics [20, 22, 31]. Interventions aiming to increase knowledge of antibiotics may promote restrictive attitude toward antibiotics, thereby contributing to reduced utilization and consequently lower selective pressure and less antibiotic resistance. A similar influence on beliefs about medications may contribute to stronger adherence, and thereby optimized effect of the antibiotic whenever a prescription is justified. This has been shown in studies of selected patient groups [32, 33].
Being male, having low education and particularly not having a health professional background was associated with a lower level of knowledge of antibiotics. The gender difference may reflect that women generally are more concerned with health issues, for instance through taking on a greater responsibility for children’s or parents’ health , or specifically through experience with antibiotic treatment. The prevalence of antibiotic use in Norway is approximately 50% higher among women than men , and the difference is largest among young adults . Regarding our questionnaire, we should also remember that awareness of vaginal yeast infection probably is higher among women and may contribute to the identified gender difference in general knowledge. Age seems influential as younger people show lower knowledge. This may indicate that the knowledge of antibiotic resistance comes from higher education or experience with antibiotic use, and is not acquired in the basic compulsory educational system. Also, healthy young people are probably less inclined to show interest in disease related topics presented in traditional media. Our results on gender and age influence are in accordance with unpublished results from a web survey commissioned by the Norwegian Directorate of Health in 2016 . Also noteworthy, is that the national campaign, which was ongoing during our data collection period, was targeted toward mothers of small children and adults 25–44 years .
As shown by a recent systematic review, the effect of public information campaigns on antibiotic prescribing tends to vary between different populations and study designs . A Norwegian study showed a reduced frequency of bacterial infections presented at emergency centres during autumn 2009 compared with previous years, suggesting an impact of the public hygiene campaign during the H1N1 influenza pandemic in 2009 . According to our findings, a campaign to increase the level of public knowledge of antibiotics in Norway would probably be most effective if targeted toward people in the less academic and particularly the male dominated professions or occupations. Additionally, increased focus on antibiotics at the primary and secondary school level would increase the knowledge among the young generations and minimize knowledge gaps due to education level when they grow older. At present, neither the core curriculum for primary, secondary and adult education in Norway nor the natural science subject curriculum specify learning objectives regarding antibiotics . A general aim is “to enable pupils to explain how the body protects itself against illness and how one can prevent and treat infectious disease”, which leaves the degree of depth on antibiotics to the teachers. A new national curriculum will be developed during 2018 with implementation planned from 2019. This represents a timely opportunity to increase the focus and knowledge of antibiotic resistance among future generations. The curriculum should perhaps make room for “…one of the biggest threats to global health, food security, and development” .
As the greatest knowledge gaps seems to be in general antibiotic knowledge, a campaign should focus on this area. Pharmacies are excellent arenas to spread correct information on antibiotics. Particularly relevant issues would be the three items with lowest rate of correct answers within antibiotics in general: side effects of antibiotics, combination with food and the concept of antibiotics versus penicillin. However, as pharmacies intercept not only people with antibiotic prescriptions but also buyers of non-prescription cough and cold products, there would be frequent opportunities to explain the difference between bacterial and viral infections, which would support the comprehension of antibiotic resistance.
Given that the national campaign was effective, which might have been the case as our findings show that women and the middle age group have higher scores, we think the Norwegian Directorate of Health should commission a similar campaign targeted toward men in vocational professions and fathers in general. This might imply different means of action, for instance different case examples and targeted messages in the campaign material. A reasonable aim for a national campaign would be to increase the public knowledge to above 80% for all knowledge items in our study.
Strengths and limitations
To our knowledge, this is the first study of its kind in Norway, thereby providing useful information on a highly relevant topic. Although our study sample in some respects deviates from the general population, the highly significant associations with antibiotic knowledge that we have identified from our material, would in all likelihood also be significant in the general population.
The master students were present to answer questions from the participants at all times during data collection. This has contributed to the completeness of data, with the maximum proportion of missing per question/statement being 2.2% (work situation). Combined with imputation of missing values on BMQ and attitude score variables, this ensured that only 6.9% of the population were excluded in the multiple linear regression analysis. The facilitation included help for participants who had difficulties understanding some of the questions. This implies a potential for overestimation of knowledge if the students were too helpful, but also underestimation if help had not been given. The students were conscious not to influence the participants’ answering, so we assume low influence from the facilitation.
The cross-sectional design prevents us from drawing conclusions regarding causal relationships. For instance, high knowledge of antibiotics may just as likely be a prerequisite for restrictive attitudes toward antibiotics as vice versa.
The study population is not representative for the Norwegian general population ≥ 18 years. Our sample is somewhat older with 36% ≥60 years compared with 28% in the general population , women were overrepresented, and the proportion with higher education was 56% compared with 33% in the general population. The estimated population average antibiotic knowledge score weighted by age, gender and education is therefore understandably lower. The question is whether it is still an overestimate. According to Statistics Norway, 12% of the Norwegian population in 2016 had a health professional education . The proportion was 27% in our study sample, and having a health professional background was the single factor with strongest influence on knowledge scores in our analysis.
There are no official statistics that demographically describe Norwegian pharmacy customers, i.e. our source population. Compared with the population who redeemed at least one prescription (The Norwegian Prescription Database, NorPD) in 2016, our study sample includes more women (68% versus 55% in NorPD), but the proportion ≥ 60 years is comparable (36% versus 37% in NorPD). However, the pharmacy customers in our study also include people merely buying over-the-counter medication and various products marketed for health and well-being. This may account for our higher proportion of younger people, and particularly women.
Our study sample is relatively large, but with a moderate response rate. The motivation to participate is probably higher among people with an interest in, or experience with, antibiotics, which may contribute to an overestimation of knowledge level. The proportion reporting antibiotic use during the previous 12 months is fairly high (30%) compared to the one-year prevalence from NorPD for 2016 (23%) , and comparable to the Eurobarometer (34%) . However, our data do not consistently support that use of antibiotics during the previous 12 months is associated with antibiotic knowledge. The response rate was particularly low in Bergen (19%) compared with Tromsø (55%) and Skien (63%). However, we found no significant association between study site and antibiotic knowledge score (data not shown), suggesting that non-response bias is not a serious threat to our estimates and interpretations.
The knowledge and attitude statements in our questionnaire were not validated, but were mainly based on questionnaires used in previous studies [11, 26], and a face validity study was conducted to ensure comprehensibility. The interpretation of the results from the following three knowledge statements would have benefited from a more precise statement formulation: whether the antibiotics with food statement is true or false, whether penicillin is another word for antibiotics and whether humans can become resistant to antibiotics.
Lack of scientific studies measuring the public’s knowledge about antibiotics and antibiotic resistance is worrying given the global call to fight antibiotic resistance. This study contributes to fill this gap. Moreover, it adds to standard surveys, like the Eurobarometer, by including measures of beliefs about medicines, attitudes toward antibiotics as well as background characteristics, thereby addressing risk factors for low level of knowledge. The study reveals knowledge gaps that should be filled and groups that should be targeted for efforts to increase the antibiotic knowledge. However, a large-scale nation-wide study would be desirable.