Knowledge of Stroke Risk Factors among Nigerians at High Risk Kolawole Wasiu Wahab, FMCP,* Olabode O. Kayode, PhD,† and Omotosho I. Musa, FWACP†
Background: Although the first step toward effective primary prevention of stroke is awareness of its risk factors, there is limited information on knowledge of these risk factors among Nigerians at increased risk. We assessed the knowledge of risk factors for stroke among Nigerians at high risk. Method: Using an interviewer-administered questionnaire in a cross-sectional design, high-risk patients (defined as those with a diagnosis of hypertension and/or diabetes) attending the specialist medical outpatient clinics of the University of Ilorin Teaching Hospital were requested to mention all the stroke risk factors they knew. The outcome measure was ability to mention at least 1 well-documented modifiable or potentially modifiable risk factor. Binary logistic regression analysis was used to determine predictors of the outcome measure. Results: The mean age of the respondents was 56.4 6 12.6 years. Only 39.8% were able to mention at least 1 well-documented modifiable or potentially modifiable risk factor; hypertension was the most recognized (34.7%). Other risk factors mentioned by the respondents were: diabetes (7.3%), alcohol intake (4.5%), smoking (3.8%), overweight and obesity (1.9%), and heart disease (.6%). Factors found to be significantly associated with ability to correctly mention at least 1 stroke risk factor were younger age (,55 years), more than 12 years of formal education, family history of stroke, urban residence, and previous health education on stroke. Conclusions: Despite being at high risk, knowledge of stroke risk factors is poor among our respondents. Intensive health education is needed to improve on this poor knowledge. Key Words: Stroke—risk factors—knowledge—high risk—Nigerians. Ó 2015 by National Stroke Association
Globally, stroke is a major cause of morbidity and mortality with resultant lifelong disability in many survivors. Whereas stroke rates have decreased significantly in developed countries of the world in the past 4 decades, the burden of the disease is increasing in the lowand middle-income countries.1,2 The reasons for the
From the *Department of Medicine, University of Ilorin, Ilorin; and †Department of Epidemiology and Community Health, University of Ilorin, Ilorin, Nigeria. Received March 27, 2014; revision received July 25, 2014; accepted July 31, 2014. This research was self-funded. Address correspondence to Kolawole Wasiu Wahab, FMCP, Neurology Unit, Department of Medicine, University of Ilorin Teaching Hospital, PO Box 738, Ilorin 240001, Nigeria. E-mail: kwwahab@ yahoo.com. 1052-3057/$ - see front matter Ó 2015 by National Stroke Association http://dx.doi.org/10.1016/j.jstrokecerebrovasdis.2014.07.053
increasing burden of stroke in the developing countries could be because of demographic and epidemiologic transitions, inadequacy of effective primary and secondary preventive measures, and lack of adequate resources for thrombolysis in patients with ischemic stroke. If unchecked, stroke is likely to further worsen the health indices in these developing countries of the world, which face a double jeopardy of rising burden of stroke and other cardiovascular diseases on one hand whereas the war against infectious diseases like multidrug-resistant malaria, tuberculosis, and human immunodeficiency virus/ acquired immune deficiency syndrome (HIV/AIDS) among others is far from being won.3 In tackling the brewing epidemic of stroke in developing countries, primary prevention will be of paramount importance. However, for an effective primary prevention, good awareness of risk factors is the first logical step before the same can be targeted for control. It has been demonstrated that there is a poor knowledge of
Journal of Stroke and Cerebrovascular Diseases, Vol. 24, No. 1 (January), 2015: pp 125-129
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stroke risk factors in the general population and in those at increased risk for the disease.4 In a hospital-based survey that assessed knowledge of stroke among healthy respondents in India, about 21% of the study population could not identify a single stroke risk factor.5 Among those at increased risk for the disease in the developed world, there appears to be a good knowledge of risk factors as only 8% of respondents in 2 separate studies in Europe and North America could not recognize any stroke risk factor.6,7 An earlier cross-sectional hospital-based study in Nigeria showed poor awareness of warning signs among suburban dwellers at increased risk for stroke.8 In spite of the growing burden of stroke in Nigeria and other African countries, there is paucity of information on knowledge of the risk factors for the disease among those at increased risk. The objective of this study was to assess the knowledge of stroke risk factors among Nigerians at high risk for the disease.
Materials and Methods Using a cross-sectional design, consecutive adult patients who gave informed consent and met the inclusion criteria were studied between August 2008 and March 2009 at the specialist medical outpatient clinics of the University of Ilorin Teaching Hospital, a tertiary health facility in north central Nigeria. Based on the records made available by the Department of Health Information Management of the hospital, the specialist medical outpatient clinics attend to an average of 2000 patients with hypertension and/or diabetes mellitus (old and new cases) annually. To obtain a 95% confidence interval (CI) of 65% around an estimated risk factor awareness level of 50%, the calculated minimum sample size for this study was 322; this was however increased by 10% to take care of nonresponders or those who would have incomplete information. An approval for the study was obtained from the ethical review committee of the hospital. The study instrument was a pretested intervieweradministered semistructured questionnaire, which was designed to obtain information on demographic and social characteristics including medical history and history of stroke in a first degree family member. Research assistants used for the study were trained in the interpretation of the study questionnaire to Yoruba, which is the major local language spoken by majority of respondents in Kwara state where the University of Ilorin Teaching Hospital is located. This training was done in anticipation of possible respondents with no/poor formal education who might be unable to adequately respond to the English version of the study questionnaire. Study respondents were patients at high risk for developing stroke, and this was defined as patients on followup for hypertension and/or diabetes mellitus at the specialist medical outpatient clinics of the hospital. It was assumed that those who had suffered stroke before
would have a better knowledge of the risk factors for the disease; hence, this category of patients was excluded from the study. By free recall and without any prompting, respondents were requested to list or mention as many stroke risk factors as they knew while information was also obtained on previous health education and sources of information on stroke. The outcome measure was ability to recognize at least 1 well-documented modifiable or potentially modifiable stroke risk factor.9 Data obtained were entered and analyzed with the Statistical Package for the Social Sciences, version 20 (SPSS Inc, Chicago, IL). Results were expressed as frequencies and percentages while odds ratios (ORs) with relevant 95% CIs were determined where applicable. Means of continuous variables were determined and compared for statistical significance with the Student t test whereas categorical variables were compared using the chi-square test. We performed a binary logistic regression analysis to determine factors associated with the ability to recognize at least 1 well-documented modifiable or potentially modifiable stroke risk factor. The independent variables assessed were age (dichotomized into #55 years and .55 years), sex, years of formal education (dichotomized into #12 years and .12 years), family history of stroke, place of residence (urban or rural), and previous health education on stroke. A P value less than .05 was taken as a measure of statistical significance.
Results Characteristics of the Respondents Out of the 354 questionnaires administered, 314 were returned with complete information giving a response rate of 88.5%. The mean age of the respondents was 56.4 6 12.6 years with 47.1% males. About 43.9% of male respondents had more than 12 years of formal education compared with 25.9% of females (P 5 .001). Hypertension was more common in male respondents (57.4% vs. 45.2%, P 5 .030) whereas a combination of hypertension and diabetes mellitus was more common in female respondents (33.1% vs. 20.3%, P 5 .010). There was no other statistically significant gender difference in the respondents. These are listed in Table 1.
Risk Factors Reported by Respondents Only 125 of the respondents (39.8%) were able to correctly mention at least 1 well-documented modifiable or potentially modifiable stroke risk factor. Hypertension was reported by 109 of the respondents (34.7%) whereas only 23 (7.3%) reported diabetes mellitus as a risk factor. Cigarette smoking and alcohol consumption were mentioned by 3.8% and 4.5% of the respondents, respectively. These are presented in Table 2.
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Table 1. Characteristics of the respondents Variable
Overall, N 5 314
Male, N 5 148
Female, N 5 166
P value
Age, mean 6 SD, y Urban residence .12 y of formal education Family history of stroke Htn alone DM alone Combined Htn and DM Previous health education on stroke
56.4 6 12.6 272 (86.6) 108 (34.4) 45 (14.3) 160 (51.0) 69 (22.0) 85 (27.1) 118 (37.6)
57.0 6 12.9 130 (87.8) 65 (43.9) 21 (14.2) 85 (57.4) 33 (22.3) 30 (20.3) 56 (37.8)
55.8 6 12.3 142 (85.5) 43 (25.9) 24 (14.5) 75 (45.2) 36 (21.7) 55 (33.1) 62 (37.6)
.410 .620 .001* .946 .030* .896 .010* .929
Abbreviations: DM, diabetes mellitus; Htn, hypertension; SD, standard deviation. Except otherwise stated, values are n (%). *P , .05.
Predictors of Ability to Identify at Least 1 Correct Stroke Risk Factor As presented in Table 3, in univariate binary logistic regression analysis, the factors found to be significantly associated with ability to correctly mention at least 1 stroke risk factor were respondent’s age less than 55 years (OR, 1.832; 95% CI, 1.160-2.893; P 5 .009), more than 12 years of formal education (OR, 2.712; 95% CI, 1.6784.382; P , .001), family history of stroke (OR, 2.112; 95% CI, 1.116-3.998; P 5 .022), urban residence (OR, 2.726; 95% CI, 1.256-5.919; P 5 .011), and previous health education on stroke (OR, 1.970; 95% CI, 1.235-3.142; P 5 .004). There was no significant association between gender and the outcome measure.
Discussion The economic and social burdens of stroke are enormous, especially in developing countries of the world where resources are meager and skilled manpower is Table 2. Stroke risk factors as reported by the 314 respondents Risk factor
n (%)
At least 1 correct risk factor* Hypertension Diabetes mellitus Cigarette smoking Alcohol consumption Stress Spiritual attack Eating fatty food Anxiety Overweight or obesity Sedentary lifestyle
125 (39.8) 109 (34.7) 23 (7.3) 12 (3.8%) 14 (4.5) 40 (12.7) 2 (.6) 1 (.3) 7 (2.2) 6 (1.9) 2 (.6)
*Any of the well-documented modifiable and potentially modifiable stroke risk factors, for example, hypertension, diabetes mellitus, cigarette smoking, alcohol consumption, and overweight or obesity.
inadequate. To reduce this high burden, there is a need for good primary prevention; successful primary prevention is however hinged on a good knowledge of the risk factors for stroke. Hypertension and diabetes mellitus are well-documented modifiable stroke risk factors,9 and the recently published results of INTERSTROKE (International Case-Control Study of the Risk Factors for Ischemic and Hemorrhagic Stroke) showed that the 2 risk factors are important in high- and low-income countries with the population attributable risk from hypertension being as high as 90.3%.10 However, in this cross-sectional study of patients with hypertension and/or diabetes mellitus, only about 40% of the respondents were able to correctly identify at least 1 welldocumented or potentially modifiable risk factor for the disease. Factors found to be significantly associated with ability to identify at least 1 correct risk factor were younger age (,55 years), better formal education (.12 years), family history of stroke, urban residence, and previous health education on stroke. In spite of being at increased risk of developing stroke, the level of knowledge of risk factors demonstrated by the respondents in this study is poor as about 60% of them could not identify a single well-documented stroke risk factor on free recall. This is similar to the findings of a Table 3. Predictors of ability to identify at least 1 risk factor
Factor Respondent’s age ,55 y Male gender .12 y of formal education Family history of stroke Urban residence Previous health education on stroke *P , .05.
Odds ratio (95% confidence interval)
P value
1.832 (1.160-2.893) .009* 1.179 (.750-1.853) .477 2.712 (1.678-4.382) ,.001* 2.112 (1.116-3.998) 2.726 (1.256-5.919) 1.970 (1.235-3.142)
.022* .011* .004*
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similar study in Switzerland where about 57% of stroke survivors could not recognize at least 1 cerebrovascular risk factor despite receiving appropriate information about their risk factor(s) at the time of stroke.11 However, only 37.6% of our respondents had ever had any form of health education on stroke, which implies that if they had previously had appropriate information on stroke risk factors, the level of knowledge demonstrated could have possibly been better. In similar separate studies in Britain6 and Canada,7 only 8% of the respondents could not recognize 1 risk factor. The difference in the level of knowledge reported in those studies and the present one could be because of a difference in the level of formal education. As observed in the our study, having a higher formal education (.12 years) increases the odds of recognizing at least 1 risk factor 2.7 folds; however, only 34.4% of our respondents had the opportunity of higher education compared with 77% reported in the British study. It is also noteworthy that although hypertension is the most recognized risk factor for stroke in this study, the level of awareness of this risk factor is poor in view of the fact that a vast majority of the respondents had hypertension either alone or in combination with diabetes mellitus; ordinarily a higher level of knowledge of these as stroke risk factors would have been expected from the study participants. It is also noteworthy that whereas 48% and 46.8%, respectively, of respondents in Britain6 and Switzerland11 were able to recognize hypertension as a stroke risk factor, only 34.7% of the respondents in the present study identified hypertension as a risk factor. The positive relationship between younger age and higher education with respect to stroke awareness has been documented previously.4,8,11,12 It is also not surprising that urban residents and those with a family history of stroke have a better knowledge of stroke risk factors. There is better access to print and electronic information in urban areas in many developing countries because of concentration of the media houses in these urban areas. Likewise, if a first degree family member has suffered from stroke, the tendency is for other members of the family to try to prevent occurrence of same in them through adoption of a healthier lifestyle, and such people are likely to seek for information on the disease. It is, thus, not surprising that the odds of having better knowledge of stroke risk factor is about 2 folds higher in those with a family member who has had stroke. An important observation of this study is that previous health education increases the odds of recognizing at least 1 stroke risk factor about 2 folds. However, as pointed out previously, just about 38% of the respondents had previous health education on the disease. It is, thus, imperative that health care workers should always educate their patients at every opportunity they come in contact with them. It would also be important to formally integrate health education into every follow-up clinic appoint-
ments (where these do not currently exist) whereas the importance of educating all stroke and high-risk inpatients cannot be overemphasized. Although the doctorto-patient ratio is low in many developing countries, it is important that doctors attending to all high-risk patients should take time to educate them on their risk, and the importance of drug compliance and lifestyle modification as this are important in primary prevention of stroke. It would also be necessary for all hospitals to have functional health education units so that at every clinic visit, patients can be adequately educated on their disease and on stroke. Because the high-risk patients seen in the clinics are members of the larger society, a community approach to health education may have greater impact in improving on the knowledge of stroke. Thus, dissemination of information through radio, television, newspapers, and hand bills would go a long way in improving stroke knowledge in the population. Information dissemination could also be through religious houses or periodic public health education programs, which can hold on market days in rural areas. The hospital-based nature of this study may potentially limit its generalization to the general population. However, in view of the paucity of information on knowledge of stroke risk factors, even among those at increased risk in Nigeria, we feel that the results would be useful in educating all patients at high risk with the ultimate aim of reducing stroke burden through primary prevention. In conclusion, this study has shown that there is a poor knowledge of stroke risk factors among those at increased risk for the disease. Efforts at improving on this poor knowledge are urgently required in view of the growing burden of stroke in developing countries in spite of inadequate manpower and facilities to adequately manage cases. Improved patient and community education on stroke and its risk factors will go a long way in primary prevention because this is better and indeed cheaper than cure!
Supplementary Data Supplementary data related to this article can be found at http://dx.doi.org/10.1016/j.jstrokecerebrovasdis.2014.07. 053
References 1. Norrving B, Kissela B. The global burden of stroke and need for a continuum of care. Neurology 2013;80(3 Suppl 2):S5-S12. 2. Mukheriee D, Patil CG. Epidemiology and the global burden of stroke. World Neurosurg 2011;76(6 Suppl):S85-S90. 3. Wahab KW. The burden of stroke in Nigeria. Inter J Stroke 2008;3:290-292. 4. Nicol MB, Thrift AG. Knowledge of risk factors and warning signs of stroke. Vasc Health Risk Manag 2005; 1:137-147.
KNOWLEDGE OF STROKE RISK FACTORS AMONG NIGERIANS 5. Pandian JD, Jaison A, Deepak SS, et al. Public awareness of warning symptoms, risk factors, and treatment of stroke in northwest India. Stroke 2005;36:644-648. 6. Slark J, Bentley P, Majeed A, et al. Awareness of stroke symptomatology and cardiovascular risk factors amongst stroke survivors. J Stroke Cerebrovasc Dis 2012; 21:358-362. 7. Gill R, Chow CM. Knowledge of heart disease and stroke among cardiology inpatients and outpatients in a Canadian inner-city urban hospital. Can J Cardiol 2010; 26:537-540. 8. Wahab KW, Okokhere P, Ugheoke AJ, et al. Awareness of warning signs among suburban Nigerians at high risk for stroke is poor: a cross-sectional study. BMC Neurol 2008; 8:18. 9. Goldstein LB, Adams R, Alberts MJ, et al. Primary prevention of ischemic stroke: a guideline from the American Heart Association/American Stroke Association Stroke Council: cosponsored by the Atherosclerotic Pe-
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ripheral Vascular Disease Interdisciplinary Working Group; Cardiovascular Nursing Council; Clinical Cardiology Council; Nutrition, Physical Activity, and Metabolism Council; and the Quality of Care and Outcomes Research Interdisciplinary Working Group: the American Academy of Neurology affirms the value of this guideline. Stroke 2006;37:1583-1633. 10. O’Donnell MJ, Xavier D, Liu L, et al, on behalf of the INTERSTROKE investigators. Risk factors for ischaemic and intracerebral haemorrhagic stroke in 22 countries (the INTERSTROKE study): a case-control study. Lancet 2010;376:112-123. 11. Croquelois A, Bogousslavsky J. Risk awareness and knowledge of patients with stroke: results of a questionnaire survey 3 months after stroke. J Neurol Neurosurg Psychiatry 2006;77:726-728. 12. Schneider AT, Pancioli AM, Khoury JC, et al. Trends in community knowledge of the warning signs and risk factors for stroke. JAMA 2003;289:343-346.
Background: Although the first step toward effective primary prevention of stroke is awareness of its risk factors, there is limited information on knowledge of these risk factors among Nigerians at increased risk. We assessed the knowledge of risk factors for stroke among Nigerians at high risk. Method: Using an interviewer-administered questionnaire in a cross-sectional design, high-risk patients (defined as those with a diagnosis of hypertension and/or diabetes) attending the specialist medical outpatient clinics of the University of Ilorin Teaching Hospital were requested to mention all the stroke risk factors they knew. The outcome measure was ability to mention at least 1 well-documented modifiable or potentially modifiable risk factor. Binary logistic regression analysis was used to determine predictors of the outcome measure. Results: The mean age of the respondents was 56.4 6 12.6 years. Only 39.8% were able to mention at least 1 well-documented modifiable or potentially modifiable risk factor; hypertension was the most recognized (34.7%). Other risk factors mentioned by the respondents were: diabetes (7.3%), alcohol intake (4.5%), smoking (3.8%), overweight and obesity (1.9%), and heart disease (.6%). Factors found to be significantly associated with ability to correctly mention at least 1 stroke risk factor were younger age (,55 years), more than 12 years of formal education, family history of stroke, urban residence, and previous health education on stroke. Conclusions: Despite being at high risk, knowledge of stroke risk factors is poor among our respondents. Intensive health education is needed to improve on this poor knowledge. Key Words: Stroke—risk factors—knowledge—high risk—Nigerians. Ó 2015 by National Stroke Association
Globally, stroke is a major cause of morbidity and mortality with resultant lifelong disability in many survivors. Whereas stroke rates have decreased significantly in developed countries of the world in the past 4 decades, the burden of the disease is increasing in the lowand middle-income countries.1,2 The reasons for the
From the *Department of Medicine, University of Ilorin, Ilorin; and †Department of Epidemiology and Community Health, University of Ilorin, Ilorin, Nigeria. Received March 27, 2014; revision received July 25, 2014; accepted July 31, 2014. This research was self-funded. Address correspondence to Kolawole Wasiu Wahab, FMCP, Neurology Unit, Department of Medicine, University of Ilorin Teaching Hospital, PO Box 738, Ilorin 240001, Nigeria. E-mail: kwwahab@ yahoo.com. 1052-3057/$ - see front matter Ó 2015 by National Stroke Association http://dx.doi.org/10.1016/j.jstrokecerebrovasdis.2014.07.053
increasing burden of stroke in the developing countries could be because of demographic and epidemiologic transitions, inadequacy of effective primary and secondary preventive measures, and lack of adequate resources for thrombolysis in patients with ischemic stroke. If unchecked, stroke is likely to further worsen the health indices in these developing countries of the world, which face a double jeopardy of rising burden of stroke and other cardiovascular diseases on one hand whereas the war against infectious diseases like multidrug-resistant malaria, tuberculosis, and human immunodeficiency virus/ acquired immune deficiency syndrome (HIV/AIDS) among others is far from being won.3 In tackling the brewing epidemic of stroke in developing countries, primary prevention will be of paramount importance. However, for an effective primary prevention, good awareness of risk factors is the first logical step before the same can be targeted for control. It has been demonstrated that there is a poor knowledge of
Journal of Stroke and Cerebrovascular Diseases, Vol. 24, No. 1 (January), 2015: pp 125-129
125
K.W. WAHAB ET AL.
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stroke risk factors in the general population and in those at increased risk for the disease.4 In a hospital-based survey that assessed knowledge of stroke among healthy respondents in India, about 21% of the study population could not identify a single stroke risk factor.5 Among those at increased risk for the disease in the developed world, there appears to be a good knowledge of risk factors as only 8% of respondents in 2 separate studies in Europe and North America could not recognize any stroke risk factor.6,7 An earlier cross-sectional hospital-based study in Nigeria showed poor awareness of warning signs among suburban dwellers at increased risk for stroke.8 In spite of the growing burden of stroke in Nigeria and other African countries, there is paucity of information on knowledge of the risk factors for the disease among those at increased risk. The objective of this study was to assess the knowledge of stroke risk factors among Nigerians at high risk for the disease.
Materials and Methods Using a cross-sectional design, consecutive adult patients who gave informed consent and met the inclusion criteria were studied between August 2008 and March 2009 at the specialist medical outpatient clinics of the University of Ilorin Teaching Hospital, a tertiary health facility in north central Nigeria. Based on the records made available by the Department of Health Information Management of the hospital, the specialist medical outpatient clinics attend to an average of 2000 patients with hypertension and/or diabetes mellitus (old and new cases) annually. To obtain a 95% confidence interval (CI) of 65% around an estimated risk factor awareness level of 50%, the calculated minimum sample size for this study was 322; this was however increased by 10% to take care of nonresponders or those who would have incomplete information. An approval for the study was obtained from the ethical review committee of the hospital. The study instrument was a pretested intervieweradministered semistructured questionnaire, which was designed to obtain information on demographic and social characteristics including medical history and history of stroke in a first degree family member. Research assistants used for the study were trained in the interpretation of the study questionnaire to Yoruba, which is the major local language spoken by majority of respondents in Kwara state where the University of Ilorin Teaching Hospital is located. This training was done in anticipation of possible respondents with no/poor formal education who might be unable to adequately respond to the English version of the study questionnaire. Study respondents were patients at high risk for developing stroke, and this was defined as patients on followup for hypertension and/or diabetes mellitus at the specialist medical outpatient clinics of the hospital. It was assumed that those who had suffered stroke before
would have a better knowledge of the risk factors for the disease; hence, this category of patients was excluded from the study. By free recall and without any prompting, respondents were requested to list or mention as many stroke risk factors as they knew while information was also obtained on previous health education and sources of information on stroke. The outcome measure was ability to recognize at least 1 well-documented modifiable or potentially modifiable stroke risk factor.9 Data obtained were entered and analyzed with the Statistical Package for the Social Sciences, version 20 (SPSS Inc, Chicago, IL). Results were expressed as frequencies and percentages while odds ratios (ORs) with relevant 95% CIs were determined where applicable. Means of continuous variables were determined and compared for statistical significance with the Student t test whereas categorical variables were compared using the chi-square test. We performed a binary logistic regression analysis to determine factors associated with the ability to recognize at least 1 well-documented modifiable or potentially modifiable stroke risk factor. The independent variables assessed were age (dichotomized into #55 years and .55 years), sex, years of formal education (dichotomized into #12 years and .12 years), family history of stroke, place of residence (urban or rural), and previous health education on stroke. A P value less than .05 was taken as a measure of statistical significance.
Results Characteristics of the Respondents Out of the 354 questionnaires administered, 314 were returned with complete information giving a response rate of 88.5%. The mean age of the respondents was 56.4 6 12.6 years with 47.1% males. About 43.9% of male respondents had more than 12 years of formal education compared with 25.9% of females (P 5 .001). Hypertension was more common in male respondents (57.4% vs. 45.2%, P 5 .030) whereas a combination of hypertension and diabetes mellitus was more common in female respondents (33.1% vs. 20.3%, P 5 .010). There was no other statistically significant gender difference in the respondents. These are listed in Table 1.
Risk Factors Reported by Respondents Only 125 of the respondents (39.8%) were able to correctly mention at least 1 well-documented modifiable or potentially modifiable stroke risk factor. Hypertension was reported by 109 of the respondents (34.7%) whereas only 23 (7.3%) reported diabetes mellitus as a risk factor. Cigarette smoking and alcohol consumption were mentioned by 3.8% and 4.5% of the respondents, respectively. These are presented in Table 2.
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Table 1. Characteristics of the respondents Variable
Overall, N 5 314
Male, N 5 148
Female, N 5 166
P value
Age, mean 6 SD, y Urban residence .12 y of formal education Family history of stroke Htn alone DM alone Combined Htn and DM Previous health education on stroke
56.4 6 12.6 272 (86.6) 108 (34.4) 45 (14.3) 160 (51.0) 69 (22.0) 85 (27.1) 118 (37.6)
57.0 6 12.9 130 (87.8) 65 (43.9) 21 (14.2) 85 (57.4) 33 (22.3) 30 (20.3) 56 (37.8)
55.8 6 12.3 142 (85.5) 43 (25.9) 24 (14.5) 75 (45.2) 36 (21.7) 55 (33.1) 62 (37.6)
.410 .620 .001* .946 .030* .896 .010* .929
Abbreviations: DM, diabetes mellitus; Htn, hypertension; SD, standard deviation. Except otherwise stated, values are n (%). *P , .05.
Predictors of Ability to Identify at Least 1 Correct Stroke Risk Factor As presented in Table 3, in univariate binary logistic regression analysis, the factors found to be significantly associated with ability to correctly mention at least 1 stroke risk factor were respondent’s age less than 55 years (OR, 1.832; 95% CI, 1.160-2.893; P 5 .009), more than 12 years of formal education (OR, 2.712; 95% CI, 1.6784.382; P , .001), family history of stroke (OR, 2.112; 95% CI, 1.116-3.998; P 5 .022), urban residence (OR, 2.726; 95% CI, 1.256-5.919; P 5 .011), and previous health education on stroke (OR, 1.970; 95% CI, 1.235-3.142; P 5 .004). There was no significant association between gender and the outcome measure.
Discussion The economic and social burdens of stroke are enormous, especially in developing countries of the world where resources are meager and skilled manpower is Table 2. Stroke risk factors as reported by the 314 respondents Risk factor
n (%)
At least 1 correct risk factor* Hypertension Diabetes mellitus Cigarette smoking Alcohol consumption Stress Spiritual attack Eating fatty food Anxiety Overweight or obesity Sedentary lifestyle
125 (39.8) 109 (34.7) 23 (7.3) 12 (3.8%) 14 (4.5) 40 (12.7) 2 (.6) 1 (.3) 7 (2.2) 6 (1.9) 2 (.6)
*Any of the well-documented modifiable and potentially modifiable stroke risk factors, for example, hypertension, diabetes mellitus, cigarette smoking, alcohol consumption, and overweight or obesity.
inadequate. To reduce this high burden, there is a need for good primary prevention; successful primary prevention is however hinged on a good knowledge of the risk factors for stroke. Hypertension and diabetes mellitus are well-documented modifiable stroke risk factors,9 and the recently published results of INTERSTROKE (International Case-Control Study of the Risk Factors for Ischemic and Hemorrhagic Stroke) showed that the 2 risk factors are important in high- and low-income countries with the population attributable risk from hypertension being as high as 90.3%.10 However, in this cross-sectional study of patients with hypertension and/or diabetes mellitus, only about 40% of the respondents were able to correctly identify at least 1 welldocumented or potentially modifiable risk factor for the disease. Factors found to be significantly associated with ability to identify at least 1 correct risk factor were younger age (,55 years), better formal education (.12 years), family history of stroke, urban residence, and previous health education on stroke. In spite of being at increased risk of developing stroke, the level of knowledge of risk factors demonstrated by the respondents in this study is poor as about 60% of them could not identify a single well-documented stroke risk factor on free recall. This is similar to the findings of a Table 3. Predictors of ability to identify at least 1 risk factor
Factor Respondent’s age ,55 y Male gender .12 y of formal education Family history of stroke Urban residence Previous health education on stroke *P , .05.
Odds ratio (95% confidence interval)
P value
1.832 (1.160-2.893) .009* 1.179 (.750-1.853) .477 2.712 (1.678-4.382) ,.001* 2.112 (1.116-3.998) 2.726 (1.256-5.919) 1.970 (1.235-3.142)
.022* .011* .004*
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similar study in Switzerland where about 57% of stroke survivors could not recognize at least 1 cerebrovascular risk factor despite receiving appropriate information about their risk factor(s) at the time of stroke.11 However, only 37.6% of our respondents had ever had any form of health education on stroke, which implies that if they had previously had appropriate information on stroke risk factors, the level of knowledge demonstrated could have possibly been better. In similar separate studies in Britain6 and Canada,7 only 8% of the respondents could not recognize 1 risk factor. The difference in the level of knowledge reported in those studies and the present one could be because of a difference in the level of formal education. As observed in the our study, having a higher formal education (.12 years) increases the odds of recognizing at least 1 risk factor 2.7 folds; however, only 34.4% of our respondents had the opportunity of higher education compared with 77% reported in the British study. It is also noteworthy that although hypertension is the most recognized risk factor for stroke in this study, the level of awareness of this risk factor is poor in view of the fact that a vast majority of the respondents had hypertension either alone or in combination with diabetes mellitus; ordinarily a higher level of knowledge of these as stroke risk factors would have been expected from the study participants. It is also noteworthy that whereas 48% and 46.8%, respectively, of respondents in Britain6 and Switzerland11 were able to recognize hypertension as a stroke risk factor, only 34.7% of the respondents in the present study identified hypertension as a risk factor. The positive relationship between younger age and higher education with respect to stroke awareness has been documented previously.4,8,11,12 It is also not surprising that urban residents and those with a family history of stroke have a better knowledge of stroke risk factors. There is better access to print and electronic information in urban areas in many developing countries because of concentration of the media houses in these urban areas. Likewise, if a first degree family member has suffered from stroke, the tendency is for other members of the family to try to prevent occurrence of same in them through adoption of a healthier lifestyle, and such people are likely to seek for information on the disease. It is, thus, not surprising that the odds of having better knowledge of stroke risk factor is about 2 folds higher in those with a family member who has had stroke. An important observation of this study is that previous health education increases the odds of recognizing at least 1 stroke risk factor about 2 folds. However, as pointed out previously, just about 38% of the respondents had previous health education on the disease. It is, thus, imperative that health care workers should always educate their patients at every opportunity they come in contact with them. It would also be important to formally integrate health education into every follow-up clinic appoint-
ments (where these do not currently exist) whereas the importance of educating all stroke and high-risk inpatients cannot be overemphasized. Although the doctorto-patient ratio is low in many developing countries, it is important that doctors attending to all high-risk patients should take time to educate them on their risk, and the importance of drug compliance and lifestyle modification as this are important in primary prevention of stroke. It would also be necessary for all hospitals to have functional health education units so that at every clinic visit, patients can be adequately educated on their disease and on stroke. Because the high-risk patients seen in the clinics are members of the larger society, a community approach to health education may have greater impact in improving on the knowledge of stroke. Thus, dissemination of information through radio, television, newspapers, and hand bills would go a long way in improving stroke knowledge in the population. Information dissemination could also be through religious houses or periodic public health education programs, which can hold on market days in rural areas. The hospital-based nature of this study may potentially limit its generalization to the general population. However, in view of the paucity of information on knowledge of stroke risk factors, even among those at increased risk in Nigeria, we feel that the results would be useful in educating all patients at high risk with the ultimate aim of reducing stroke burden through primary prevention. In conclusion, this study has shown that there is a poor knowledge of stroke risk factors among those at increased risk for the disease. Efforts at improving on this poor knowledge are urgently required in view of the growing burden of stroke in developing countries in spite of inadequate manpower and facilities to adequately manage cases. Improved patient and community education on stroke and its risk factors will go a long way in primary prevention because this is better and indeed cheaper than cure!
Supplementary Data Supplementary data related to this article can be found at http://dx.doi.org/10.1016/j.jstrokecerebrovasdis.2014.07. 053
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