State of knowledge of Cameroonian drug prescribers on pharmacovigilance

Introduction The present study conducted in Cameroon from June 2013 to February 2014 aimed to estimating the level of pharmacovigilance knowledge and practice of health professionals in Cameroon. Methods We conducted a descriptive cross-sectional survey on 149 health professionals in Cameroon from June to September 2013. Data were analyzed using software IBM SPSS 20.0. We calculated proportions and odd ratio, and confident interval of their values, keeping a threshold of p of 0.05 to determine the level of significance. Results Ninety percent (90%) of declaration of side effects were made to the medical representatives and 4% to the National Pharmacovigilance Centre. Fifty four percent (54%) of physicians were not aware of the existence of a National Pharmacovigilance system. Ten (10%) of prescribers had never heard of pharmacovigilance, however respondents answered unanimously that they need training on pharmacovigilance. A wrong definition was given by most of the nurses and dentists (61,1% and 58,3% respectively) as compared to physicians and pharmacists (respectively 15.2% and 26,5%). Given the results of this study, the establishment of a National Pharmacovigilance system based on a solid legal foundation is necessary in Cameroon. This implementation must go through the involvement of all stakeholders and their awareness raising on the importance of this activity and its positive impact on the health of populations. Conclusion Pharmacovigilance is a public health problem in Cameroon, with due to lack of good knowledge and practice of prescribers, precisely physicians, pharmacists, nurses, and dentists who are not always aware of an existing pharmacovigilance system in Cameroon.


Introduction
Durgs side effect has been widely studied through pharmacovigilance studies since the thalidomide problem [1].
Pharmacovigilance is widely spread and applied in European countries [2,3] and USA [4], and more and more in developing countries [5] where the health system makes a case of health professional training [6]. Drugs are widely used nowadays to fight diseases that threaten the lives and well-being of people in the world, particularly in Africa and hence the Cameroon. In this country, the drug represents a burden for patient as it could already be observed in a study since 1997 [7]. Though [8]. Several pilot projects have been attempted in this part of Africa, showing in most of cases that pharmacovigilance is a major public health problem, and the need of improvement action to improve the situation [9]. Majority of these pilot projects are usually related to vertical programs malaria, ARV or vaccination types. In addition, they often reveal gaps in knowledge of the actors, in addition to a lack of infrastructure and communication device. Since the historical drama of Thalidomide, international scientific community immediately realized that despite clinical trials, with a good follow up, a drug remains dangerous after being placed on the market. Therefore, in order to avoid harm to patients and improve public health, it is essential to establish a wellorganized system of pharmacovigilance. It also appears as an essential component of an effective drug regulation system, clinical practice and health programs. Despite the call from WHO to strengthen national pharmacovigilance systems, developing countries are still struggling to seriously include ir pharmacovigilance in their health information system. This goes through the assessment of health professional knowledge and practice of pharmacovigilance. Cameroon, this is not known, thus our motivation to carry out this study aiming to assess the health professional knowledge and practice of pharmacovigilance in this country.

Methods
From June to September 2013, we carried out a study on a sample drawn from a synthetized database of 12526 health professionals composed of physicians, pharmacists and dentists in registered as shown in the national health statistics report of Cameroon in 2010.
We asserted that 10% of prescribers have no "knowledge" of pharmacovigilance. We therefore calculated a sample of 138 patients, with an error margin of 5% and a confident level of 95% using Epi Info statcalc. We extended our selection to the four groups as not only physicians prescribe drugs in Cameroon. We sent out to the sample population 200 questionnaires and received 149 exploitable responses. We analyzed data using IBM SPSS 20.0 software. We applied a 0.05 threshold for p-value for statistical significance when comparing proportions.

Results
Our sample was composed of 55 % of males. We had 57 % of physicians, 23 % of pharmacists, 12 % of nurses and 8 % of dentists. Nearly all our respondents had already prescribed, as well as observed a side effect, which in half of cases was from a drug prescribed by them ( Table 1). Of the reason the cases were not declared, not knowing to whom to declare was the first, followed by lack of adequate contact of where to declare ( Table 2). Nearly all the declared cases were done through the drug representatives of pharmaceutical companies (Figure 1). Physicians and pharmacists gave the less wrong definition of pharmacovigilance than dentists and nurses. More of physicians and pharmacists also believed there was no functioning pharmacovigilance system in Cameroon ( Table   3). were not aware of an existing functional pharmacovigilance system in Cameroon; which is less than findings in a survey in a similar poor resource setting in 2013 [11]. Informing pharmaceutical companies' drug representatives rather than national system shows on one hand the willing to declare, but also the lack of strict regulation on procedures in reporting such events. The only few reported cases received at ministry of health levels come from vertical programs in general, as observed in vaccine program side effects follow-up [12]. Comparably to a study in Senegal in 2013 [13] most of the dentists in our country are not aware of such a system though they are potential important prescribers as shown in similar settings.

Conclusion
Pharmacovigilance is a public health problem in Cameroon and the problem due to lack of good knowledge and practice of prescribers precisely physicians, pharmacists, nurses, and dentists who are not always aware of an existing pharmacovigilance system in Cameroon.

Competing interests
Authors declare not competing interests.

Authors' contributions
All authors contributed actively to each part of the research. The author has read the final version of this manuscript. Table 1: prescription behavior Table 2: reason of non-declaration of side effects Table 3: pharmacovigilance status of knowledge of prescribers   Physicians and pharmacists gave the less wrong definition of pharmacovigilance than dentists and nurses. More of physicians and pharmacists also believed there was no functioning pharmacovigilance system in Cameroon Did not foresee the importance 55 09,0%

Tables
Did not know it should be declared 54 05,5% Did not have the « means » to declare 56 03,6% The patient did not want the side effect to be declared. 55 05,5% Of the reason the cases were not declared, "not knowing to whom to declare" was the first, followed by "lack of adequate contact of where to declare" Page number not for citation purposes 6 Figure 1: place of side effects cases declaration