Knowledge and awareness of personal sickle cell genotype among parents of children with sickle cell disease in southeast Nigeria

Abstract

Sickle cell trait (SCT; HbAS), the heterozygous state for the sickle cell allele of the beta globin gene, is carried by as many as 100 million individuals worldwide. Nigeria has the highest prevalence of SCT, impacting an estimated 25 % of adult population. This study was designed to assess timing of awareness, knowledge of SCT status and preferred method of education among parents of children with sickle cell disease (SCD). We conducted a cross-sectional survey of parents of children with SCD from June 2013–March 2014. Participants completed a 20-item questionnaire to assess (1) awareness of personal sickle cell genotype, (2) timing of awareness of personal sickle cell genotype, and (3) knowledge of SCT. One hundred and fifty-five participants completed the survey. Seventy-eight percent were females, and 87 % (135/155) were aware of their own sickle cell genotype. Timing of awareness varied as follows: following birth of a child with sickle cell disease (45 %); during marriage (21.5 %); school admission (9.6 %); during pregnancy (9.6 %); and other times (14 %). Approximately 35.5 % of participants thought that sickle cell trait was a mild form of sickle cell disease. Radio (43.9 %), informational community meetings (27.7 %), and television (21.9 %) were identified by participants as the most effective method of increasing sickle cell trait awareness. Innovative approaches are needed to increase the proportion of individuals who are aware of their own sickle cell genotype prior to having a child with sickle cell anemia in line with the Healthy People 2020 objective.

Electronic supplementary material

The online version of this article (doi:10.1007/s12687-015-0225-5) contains supplementary material, which is available to authorized users.

Introduction

Sickle cell disease includes a variety of pathologic conditions resulting from inheritance of sickle hemoglobin (Hb) either in a homozygous state (SS) or in a heterozygous state with another abnormal hemoglobin such as SC, Sβthal, SOArab, SD, and SG (Aken’ova 2013). The most common and most severe type is the homozygous state (SS) known as sickle cell anemia (SCA) associated with chronic severe hemolytic anemia and vaso-occlusion (Adekile and Adeodu 2007; Hoffbrand et al. 2001; Martin and Pearson 1997). In addition to medical complications associated with SCA, it is also associated with psychosocial complications (Ola et al. 2013). Globally, it is estimated that about 305,000 newborns are born annually with SCA, and the global burden has been shown to be on the increase (Piel et al. 2013). The increasing number of SCA will continue to have a major impact particularly on healthcare services and financing (Piel et al. 2013).

Sickle cell trait (SCT; HbAS), the heterozygous state for the sickle cell allele of the beta globin gene, is carried by as many as 100 million individuals worldwide including an estimated 2.5 million Americans (National Heart 2012). Although found among all racial groups, individuals of African descent has the highest prevalence (Serjeant 2013; WHO 2006). SCT confers a survival advantage relative to individuals with normal Hb in malaria endemic region where the largest number of individuals with SCT reside (Serjeant 2013). On the other hand, SCT also improves life expectancy relative to SCA (WHO 2006). The prevalence of SCT varies widely from region to region and reaches up to 40 % in parts of West Africa (Serjeant 2013; WHO 2006). In Nigeria, the prevalence SCT is estimated at 24 % (Taiwo et al. 2011; WHO 2006). It is estimated that there are more than 40 million individuals who carry the sickle cell trait in Nigeria and more than 150,000 children born each year with SCA (Galadanci et al. 2014).

Though the frequency of sickle cell trait predicts the prevalence of SCA, awareness and knowledge of sickle cell trait status may help reduce the prevalence of SCA (Ezechukwu and Chukwuka 2004; Nnaji et al. 2013; WHO 2006). It is estimated that a significant proportion of individuals in Nigeria are unaware of their sickle cell genotype prior to marriage (Ezechukwu and Chukwuka 2004). A recent study on the attitudes and awareness of youths in the Yaba Development Area found that 55 % of youths in the age group of 15–19 years old had no exposure to SCA premarital counseling (Oludare and Ogili 2013). This same group also scored lowest in SCA knowledge and had the highest rate of negative attitudes towards SCA (Oludare and Ogili 2013).

Despite the high prevalence of both SCT and SCA in Nigeria, there is no universal newborn screening program and no uniform premarital testing for sickle cell genotype, which results in children with sickle cell disease being identified during an illness when their genotype is performed based on clinical suspicion. In most cases, this is also the time when the genotype of their parents is obtained. There is a paucity of data on the awareness of SCT status in parents of children with SCA. Studies from Nigeria assessed the SCT awareness in unmarried general population (Nnaji et al. 2013; Oludare and Ogili 2013).

Increasing the proportion of individuals who are aware of their sickle cell genotype is a stated priority of the Healthy People 2020 objectives and the World Health Organization’s 2006 sickle cell resolution (USDHHS 2013; WHO 2006). Current modeling projects a 50 % increase over present levels of annual SCA births in Nigeria by the year 2050 (Piel et al. 2013). This dramatic projection indicates the need to identify methods to increase awareness and education levels related to SCT and SCA. The most appropriate time for individuals to become aware of their sickle cell genotype is not well described. Although universal newborn screening for sickle cell genotype has been in place in the USA, a recent study showed that a significant proportion of adolescents are unaware of their sickle cell genotype (Chandnani et al. 2013). A recent survey of Nigerian physicians living in the USA indicates that most would recommend individuals become aware of their own genotype prior to marriage (Shahani et al. 2013). This same cohort of participants indicates that individuals with sickle cell anemia should be identified as soon after birth as possible. This study was designed to assess the knowledge, timing of awareness of SCT status among parents of children with SCA and determine preference among participants on the best method of sickle cell education. We hypothesize that a majority of participants would become aware of their own genotype only following the birth of their child with sickle cell anemia.

Subjects and methods

Setting, design, and study population

A cross-sectional survey of parents attending the sickle cell clinic at the University of Nigeria Teaching Hospital (UNTH), Enugu.

Participant recruitment, inclusion, and exclusion criteria

All parents of children with SCA attending the Sickle Cell Clinic of UNTH over the study period and who consented to study were recruited consecutively. Non-biologic parents or caregivers of children with sickle cell anemia were excluded.

Study procedure

Parents attending clinic were approached to participate in the study. Study purpose was explained to parents in their preferred language of English or local Nigerian language. Following explanations, written informed consent was obtained from all participants prior to completing survey. The investigators then administered a structured questionnaire designed to obtain demographic information including parental education, occupation, and religion. Questionnaire also sought sickle cell-specific information including awareness of genotype, time of awareness, and perception of SCT and SCA.

Statistical analysis

Statistical analysis was performed using SPSS statistical program version 22 (IBM Corp Released 2013). Chi-square test was used to compare frequencies and to test the association between differences in proportion, whereas Pearson’s correlation coefficient was employed to test the relationship between two numerical variables. The level of significance was set as p < 0.05. The knowledge scores were summed on a binary basis with 1 point being assigned for a correct answer and 0 being given for an incorrect response. Scores of 3–6 was considered a low to average sickle cell trait knowledge, while scores of 7 and 8 were considered to be an indicator of high sickle cell trait knowledge. Multivariate analysis was performed to identify predictors of knowledge. The study protocol was approved by the UNTH Health Research Ethics Committee.

Results

Participant characteristics

A total of 273 children with SCA attended the sickle cell clinic during the study period. One hundred fifty-five (155) parents were approached to participate in the study, and all completed the survey for a response rate of 100 %. The remaining 118 were non-biologic parents, caregivers, or adolescents who attended alone and these were all excluded. Table 1 details the characteristics of the study population. Each survey was completed by one member of a married couple with over three-quarters (78.1 %) of the responses coming from females and 21.9 % were completed by males. The mean age of the respondents was 39.2 years with a median of 38 years. Approximately three-fourths (76.1 %) of the subjects had a secondary or higher education. Participants completing the survey were generally working adults with 85.2 % reporting their status as employed or self-employed. The vast majority (98.7 %) of respondents identified their faith as being of Christian denomination.

Table 1.

Participant characteristics

Characteristic	Informant N = 155		Spouse N = 155
	Number	Percent	Number	Percent
Sex
Male	34	21.9	121	78.1
Female	121	78.1	34	21.9
Age
23–29	21	13.5	9	5.8
30–39	68	43.9	45	29.0
40–49	46	29.7	55	35.5
50–59	14	9.0	40	25.8
60–69	6	3.9	6	3.9
Education level
None	2	1.3	3	1.9
Primary	35	22.6	40	25.8
Secondary	63	40.6	62	40.0
Tertiary	55	35.5	50	32.3
Employment status
Employed	66	42.6	60	38.7
Self-employed	66	42.6	85	54.8
Unemployed	21	13.5	9	5.8
Retired	2	1.3	1	0.6
Religion
Christian	153	98.7	152	98.1
Muslim	2	1.3	3	1.9

Awareness of SCT genotype

Among the 155 respondents, 135 (87.1 %) were aware of their sickle cell trait. Participants that were aware of their trait status had two follow-up questions as shown on Table 2. The first asked respondents to identify their trait. While no subject self-identified as having sickle cell disease, the overwhelming majority (99.3 %) reported having an AS genotype. A majority of respondents (45.2 %) became aware of their own sickle cell genotype following the birth of a child with sickle cell disease. Marriage (21.5 %) was the next most common response. Marriage, pregnancy, and birth of a child with SCA combined for over three-quarters (76.3 %) of the events at which respondents became aware of their genotype.

Table 2.

Awareness of SCT genotype

Characteristic	Informant N = 155		Spouse N = 155
	Number	Percent	Number	Percent
Aware
Yes	135	87.1	128	82.3
No	20	12.9	27	17.4
If yes, what
AA	1	0.7	5	3.9
AS	134	99.3	122	95.3
SS	0	0.0	1	0.8
Time of awareness
Knowledge sake	17	12.6	11	8.6
School admission	13	9.6	3	2.3
Employment	1	0.7	4	3.1
Marriage	29	21.5	33	25.8
Child with SS	61	45.2	72	56.3
Pregnancy	13	9.6	4	3.1
Other	1	0.7	1	0.8

SCT knowledge scores

Responses to specific knowledge on sickle cell are shown on Table 3. A significant proportion of respondents (35.5 %) thought sickle cell trait is a mild form of sickle cell disease. Almost 40 % of respondents misidentified the proportion of Nigerians with sickle cell trait and the probability of having a child with sickle cell anemia when two parents have the sickle cell trait. Participants with tertiary education were significantly more likely to score high on the knowledge score (74.5 %) compared to individuals with lower education (53 %). Men also had significantly higher knowledge score (74.5 %) compared to women (56.2 %).

Table 3.

Sickle cell trait knowledge scores

Question	Correct	Incorrect	Percentage correct
How does someone get SCT	193	16	89.7
To inherit sickle cell disease, both parents must have at least one sickle cell gene	152	3	98.1
Blood testing can confirm sickle cell trait	153	2	98.7
It is important to know if you have sickle cell trait even if asymptomatic	153	2	98.7
Sickle cell trait is a mild form of sickle cell disease	100	55	64.5
People with sickle cell trait have symptoms of sickle cell disease	128	27	82.6
1 in 4 Nigerians have sickle cell trait	94	61	60.6
If both parents have sickle cell trait, there is a 25 % chance the child will have sickle cell disease	94	61	60.6

Predictors of knowledge score

The timing of the awareness was a statistically significant (p = 0.012) predictor of a respondent having a high knowledge score, in that individuals who discovered their sickle cell trait after the birth of a child with sickle cell disease were almost two and a half times (odds ratio (OR) 2.493) as likely to have a score indicating high knowledge in comparison to individuals who discovered their sickle cell trait prior to the birth of a child (Table 4).

Table 4.

Predictors of knowledge score

	Low to average knowledge score (3–6)		High knowledge score (7–8)		Total	Pearson’s (p value)	Odds ratio	95 % CI lower	95 % CI upper
	Number	Percent	Number	Percent
Sex
Male	13	38.2	21	61.8	34	0.336	1.198	0.648	2.214
Female	53	43.8	68	56.2	121	(0.695)	0.951	0.806	1.123
Age
<40	37	41.6	52	58.4	89	0.087	1.042	0.791	1.374
≥40	29	43.9	37	56.1	66	(0.870)	0.946	0.655	1.366
Education
Less than university	48	48.0	52	52.0	100	3.385	0.803	0.639	1.010
University or 1 greater	18	32.7	37	67.3	55	(0.089)	1.524	0.958	2.426
Timing of awareness							2.493	1.259	4.934
After birth of SS child	18	29.5	43	70.5	61	7.030	1.772	1.131	2.775
Pregnancy or before	48	51.1	46	48.9	94	(0.012)	0.711	0.554	0.912

SCT increasing awareness

Figure 1 describes the responses given by respondents when asked to identify the best outreach method for increasing sickle cell trait awareness in the population. A majority of respondents (44 %) suggested that public education using radios would be the most effective method of education followed by 27.7 % who identified community meetings as a potential effective method of education.

Fig. 1.

Suggestions for increasing SCT awareness

Discussion

Findings from this study indicate that a majority of parents in this cohort became aware of their own sickle cell genotype following the birth of a child with sickle cell anemia. The mean age of 39.2 years is higher than the mean age of 23.35 years documented in another study in Nigeria (Oludare and Ogili 2013). This was not unexpected as the study participants were unmarried youths compared to current study among married adults.

A higher proportion of respondents in this study was aware and correctly identified their genotype in comparison to only 55 % awareness among respondents in a recent study in the same population (Galadanci et al. 2014). However, the study was conducted among all mothers and not specifically mothers who have a child with sickle cell anemia. It is not surprising that mothers without children with SCA are less likely to know their genotype than those with such children. As we hypothesized, the birth of a child was the most common event at which participants became aware of their own sickle cell trait carrier status. Earlier awareness of the sickle cell genotype could provide information to make decisions about potential partners who also have the sickle cell trait and could prevent the birth of a child with SCA following the modeling proposed by Piel et al. (2013). Although no specific time has been identified for individuals to become aware of their sickle cell genotype, consensus seems to be that this should occur before marriage (Ezechukwu and Chukwuka 2004; Nnaji et al. 2013; Taiwo et al. 2011). Some investigators advocate that this should occur during adolescent to provide information early enough in relationship to make procreational descisions (Oludare and Ogili 2013). Studies have shown that latter awareness of genotype has led to cancellation of marriages with associated societal consequences (Nnaji et al. 2013; Taiwo et al. 2011).

A recent study found that participants recommended more public enlightenment campaign on sickle cell using processes such as media, social media, internet, schools, churches, outreaches, and seminars (Oludare and Ogili 2013). This is similar to findings in this study where respondents identified radio as the most effective method of increasing sickle cell trait awareness. Other suggested modes were informational meetings in the community and television.

A significant proportion of respondents (35.5 %) in this study thought sickle cell trait is a mild form of sickle cell disease which is similar to other studies that has identified significant misunderstanding about sickle cell trait indicating the need for identification of innovative and effective approaches to increase public awareness and knowledge of sickle cell trait and anemia (Acharya et al. 2009).

Findings from this study also identified educational level (tertiary education) and gender (male sex) as predictors for higher knowledge of sickle cell trait. It is noteworthy in this study that parents who discovered their sickle cell trait status after the birth of a child with SCA were more likely to exhibit high knowledge compared to those who discovered their trait prior to the birth of a child with SCA. A plausible explanation could be that individuals who became aware of their sickle cell trait after their child was born had this discovery made at a medical facility (probably during child’s ill health or admission) where educators/healthcare givers were able to sit down with the family and provide a detailed explanation of sickle cell trait and SCA. This underscores the importance of education and genetic counseling in improving knowledge of sickle cell trait and SCA. This improved knowledge following education and genetic counseling has been demonstrated in other studies (WHO 2006).

Our study has limitations. It is a single site study and as such has limited generalizability although other studies have shown similar low awareness and knowledge of sickle cell in Nigeria (Alao et al. 2009; Ezechukwu and Chukwuka 2004; Olakunle et al. 2013; Owolabi et al. 2011). It is plausible that community-based interventions as recommended by participants will increase awareness and knowledge of sickle cell, the feasibility, effectiveness and cost-effectiveness of such interventions have not been proven.

A majority of parents of children with sickle cell disease became aware of their own genotype after the birth of their child. Innovative approaches are needed to translate available evidence-based interventions to sustainable community-based programs in order to realize the Healthy People 2020 goal of increased awareness and knowledge among individuals with hemoglobinopathies.