Perceptions of doctors to adverse drug reaction reporting in a teaching hospital in Lagos, Nigeria

Adverse drug reactions (ADRs) are global problems of major concern. They affect both children and adults with varying magnitudes, causing both morbidity and mortality [1–4]. In addition to the human costs, ADRs have a major impact on public health by imposing a considerable economic burden on the society and the already-stretched health-care systems [5, 6]. Post marketing surveillance of drugs is very important in analysing and managing the risks associated with drugs once they are available for the use of the general population. Spontaneous reporting has contributed significantly to successful pharmacovigilance. The contribution of health professionals, in this regard, to ADRs databases is enormously significant and has encouraged ongoing ascertainment of the benefit-risk ratio of some drugs [7, 8] as well as contributed to signal detection of unsuspected and unusual ADRs previously undetected during the initial evaluation of a drug [9, 10]. In spite of these benefits, under-reporting remains a major draw-back of spontaneous reporting [10, 11]. It is estimated that only 6–10% of all ADRs are reported [12, 13]. This high rate of under-reporting can delay signal detection and consequently impart negatively on the public health.

Many factors are associated with ADRs under-reporting among health professionals. These factors have been broadly classified as personal and professional characteristics of health carers, and their knowledge and attitudes to reporting [11]. Inman [14] has summarized these factors as the 'seven deadly sins'. His description of the 'sins' include: attitudes relating to professional activities (financial incentives: rewards for reporting; legal aspects: fear of litigation or enquiry into prescribing costs; and ambition to compile or publish a personal case series) and problems associated with ADR-related knowledge and attitudes (complacency: the belief that very serious ADRs are well documented by the time a drug is marketed; diffidence: the belief that reporting an ADR would only be done if there was certainty that it was related to the use of a particular drug; indifference: the belief that the single case an individual doctor might observe could not contribute to medical knowledge; and ignorance: the believe that it is only necessary to report serious or unexpected ADRs), and excuses made by professionals (lethargy: the procrastination and disinterestedness in reporting or lack of time to find a report card and other excuses). Lopez-Gonzalez et al [11], in their review of determinants of ADRs under-reporting from the global perspective, have shown that three of the seven 'sins' proposed by Inman that are associated with professional activity (financial incentives, fear and ambition to publish) seem to contribute less significantly to under-reporting. Insecurity (the belief that it is nearly impossible to determine whether or not a medicine is responsible for a particular ADR) is another factor associated with under-reporting [11] but was not proposed by Inman. It therefore appears that factors that promote under-reporting may vary from one country to another.

The determinants of ADRs under-reporting have not been extensively studied in Africa. Only two studies have analysed these factors in African countries [15, 16]. A previous study from Nigeria has indicated inadequate knowledge of resident doctors about ADRs [17]. However, the study excluded other cadres of doctors, it did not evaluate attitudes that were associated with under-reporting and did not assess the in-depth knowledge of the doctors about ADRs reporting.

This study was therefore aimed at investigating the knowledge and attitudes of doctors to ADR reporting in a teaching hospital in Lagos, Nigeria and to suggest possible ways of improving spontaneous reporting based on our findings.

This study has shown inadequate knowledge of doctors about ADRs and reporting similar to the previous reports among resident doctors in Nigeria [17] and doctors in many countries across Europe [18, 22–24], America [25, 26] and Asia [27, 28]. Perhaps, the undergraduate training in pharmacovigilance and medicine risk perceptions may be either insufficient or improperly delivered to prepare the doctors for the task of ADR monitoring and reporting in their future career.

Spontaneous ADR reporting by other health professionals and individuals is practiced in many countries [29–31] and it is recommended by the NPC [32] but not recognised by the respondents. This is reflected in their low percentages that considered individuals and physiotherapists qualified to report ADRs. A significant number of the respondents were not aware of the existence of a national pharmacovigilance centre in Nigeria and amongst those who were aware, only 39.2% were able to correctly identify Abuja as the office. Lack of knowledge of where ADRs should be reported would automatically affect reporting, therefore, awareness programmes; through publicity, would appear necessary to improve ADR reporting in Nigeria.

The general lack of awareness of ADR reporting system in Nigeria was reflected by the 63.4% of the respondents who did not know about the existence of a Yellow Card reporting scheme coupled with the fact that only two respondents had ever reported ADRs with a Yellow Card. This proportion is rather very low when compared to a similar reporting scheme among doctors in the United Kingdom [19], America [25], Netherland [33], Spain [34], China [28] and India [35]. The differences in the reporting rates may be attributed to the priority, attention and commitment given to pharmacovigilance by the government of these countries. Such attitudes need to be emulated by the Nigerian government.

When we compared the factors that may influence reporting by the respondents with those reported by Lopez-Gonzalez et al [11], the results were similar. Our study has shown that, like most countries around the world, ignorance (not feeling the need to report well recognised reaction), diffidence (concern that the ADR report may be wrong) and indifference (lack of time to fill in a report and a single unreported case may not affect ADR database) (Table 2) would significantly influence ADR-reporting among the doctors working in a Nigerian teaching hospital. However, complacency, fear, financial incentives and bureaucracy involved in filling in the Yellow Card would have a little influence on the respondents to report ADRs. Therefore ADR under-reporting in Nigeria appears to be associated more with knowledge gaps and attitudes of the doctors rather than with personal and professional characteristics reported in other studies [18, 19, 36, 37]. Previous studies have shown that distribution and availability of Yellow Cards to the doctors increase ADRs reporting [22, 38] but unfortunately, a very high proportion of the respondents did not consider this as an important means of improving reporting.

Most of the respondents were willing to report reactions to newly marketed drugs and serious reactions to established products because they perceived post-marketing surveillance as an important part of pharmacovigilance. Globally, vaccines and antibiotics are among the leading causes of ADRs, especially in children [39–42]. In addition to antibiotics, herbal medicines and antimalarial drugs have contributed significantly to ADRs in Nigeria [39]; this may therefore explain the higher number of respondents who would report serious ADRs to these drugs when compared with OTC drugs and topical agents. Post marketing drug surveillance encouraged ADR reporting if reaction was serious and unusual in nature. These encouraging factors were recognised by over 70% of the respondents. The NPC is known not to receive reports of proven reactions [32]. The respondents may probably not be aware of this as 46.5% of them would report a well recognised reaction to a particular drug.

Anxiety of respondents not to appear incompetent or become subject of ridicule may cause them to want to report only ADRs that they consider certainly were caused by a drug. Such fear may probably explain the 45.5% respondents with this response which is a consistent finding in other studies [18, 21]. The need to allay this fear, through sensitisation and pharmacovigilance education by NAFDAC, cannot be over-emphasized.

The five hypothetical examples of ADRs reportable to NPC were recognised by 30% to 50% of the respondents. These values are rather low. Palpitation with the use of coartem, skin rashes to roxithromycin, and jaundice to frusemide were more recognised than thrombocytopenia to heparin and gastrointestinal bleeding to diclofenac as unusual reactions. The NAFDAC may need to formulate a guideline for health professionals to improve recognition of unusual ADRs.

Educational intervention has been shown to improve ADR reporting in Portugal [43] and Rhode Island in the USA [36]. Education and training on spontaneous ADR reporting and how to use the Yellow Card is very necessary among the doctors since only one respondent had ever received such training. Almost all the respondents showed interest in education and training. Continuous Medical Education, training and refresher courses were the most cited means of improving ADR reporting. This certainly shows that the doctors are willing to improve their knowledge of ADR reporting and increase their participation in the Yellow Card reporting scheme if education and awareness on the reporting scheme is instituted in the hospital. The other methods recommended by the respondents such as instituting and encouraging feedback between patients, prescribers and dispensers of drugs, receiving reminders and increased awareness from ADR Monitoring Committee, and increasing the awareness of other healthcare professionals on reporting ADRs are very important and can certainly be considered as examples of a good practice that should be instituted in the hospital. Most of the factors considered unimportant to improve ADR reporting (Table 4) had been implemented in the developed countries and have yielded good results [14, 18, 19, 44]. Efforts should be made at implementing these methods in the teaching hospital.

The objective of this study was to evaluate the attitudes and knowledge of doctors in a teaching hospital in Lagos, Nigeria to spontaneous ADR reporting. However, this study was limited by not comparing the attitudes and knowledge of the doctors with their years of practice and position/level. This is likely to be addressed in our future studies. It would be logical to extend this study to other teaching hospitals in Nigeria to enable us generalise our findings.

There are gaps between knowledge and ADRs reporting among doctors working in a teaching hospital in Lagos, Nigeria. These gaps need to be filled by improved training in pharmacovigilance and risk perceptions of drugs. It may take the doctors some time to fully accept ADR reporting as a role if continuous medical education, reminders and awareness on the Yellow Card reporting scheme are not instituted in the hospital. Attitudinal and cultural changes, whereby ADR reporting is seen as an integral part of the clinical activities of the doctors, are very necessary for a long term improvement of ADR reporting.