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Logo of nihpaAbout Author manuscriptsSubmit a manuscriptHHS Public Access; Author Manuscript; Accepted for publication in peer reviewed journal;
 
Am J Med Genet A. Author manuscript; available in PMC 2010 November 1.
Published in final edited form as:
PMCID: PMC2784105
NIHMSID: NIHMS146522

Maternal Knowledge and Attitudes about Newborn Screening for Sickle Cell Disease and Cystic Fibrosis

Abstract

Illinois introduced mandatory newborn screening (NBS) for sickle cell disease (SCD) in 1989 and for cystic fibrosis (CF) in 2008. We examined maternal understanding of NBS for SCD and CF, and their knowledge of the genetics, symptoms and treatments of both conditions. Our methods consisted of conducting interviews of inpatient post-partum women (>18 years and English speaking). Our results showed that of the 388 eligible participants, 34 self-identified as sickle cell carriers, 1 with SCD and 1 as a CF carrier. Almost 3/4 were African American (282/387). Although all but 5 women had prenatal care, only 35% (133/378) recalled their prenatal care provider mentioning NBS, and only 56% (217/388) of participants recalled nursery staff mentioning NBS. There was more self-reported familiarity with SCD (3.32/5) than CF (1.97/5, p<0.001). Over 2/3 (260/388) of participants could not answer CF knowledge questions because they had never heard of CF. Among those who had heard of the conditions, mean knowledge scores were 66% for SCD (n=372) and 63% for CF (n=128). Bivariate analysis identified education, age, race, marital status, and insurance status as statistically significant. After linear regression education remained significant for both conditions. We conclude that in a sample of predominantly African American post-partum women, we found poor understanding of NBS, greater familiarity with SCD, and significant knowledge gaps for both SCD and CF. There are many missed educational opportunities for educating parents about NBS and specific conditions included in NBS panels in both the obstetric clinics and the nursery.

Keywords: newborn screening, sickle cell disease, cystic fibrosis, parental understanding, knowledge, attitudes and beliefs

INTRODUCTION

Newborn screening (NBS) for phenylketonuria (PKU) became possible in the early 1960s when Guthrie developed both the bacterial inhibition assay to measure phenylalanine from blood and the filter paper on which to collect and test the blood samples [Guthrie and Susi, 1963]. In 1963, Massachusetts became the first state to pass mandatory NBS legislation for PKU screening. Guthrie and the National Association for Retarded Children (NARC now known as the ARC) lobbied for mandatory screening to ensure that all children with preventable retardation were identified and most states adopted such legislation [Koch, 1997]. Today, mandatory NBS exists in 48 states; parental consent is needed in the other two.

One concern with a mandatory screening program is what parents understand. When consent is needed, health care providers must ensure, at minimum, that parents know that screening is being done and that the parents agree to its performance. Ideally, health care provider would also explain why the test is being done, what the risks and benefits are, and what follow-up the parents can expect. Although mandatory screening does not preclude such discussions, data show that they often do not occur [Campbell and Ross, 2003; Davis et al., 2006; Detmar et al., 2007].

Discussions about NBS are important because lack of parental understanding may cause harm. If parents do not understand that an abnormal NBS result requires diagnostic testing to confirm or refute a presumptive diagnosis, they may fail to obtain appropriate follow-up in a timely manner and threaten the success of reducing morbidity and mortality [Arn, 2007; James and Levy, 2006; Miller et al., 1990].

In Illinois, NBS has existed since 1965 and has always been mandatory. In this manuscript, we examine parental understanding of NBS for two conditions, sickle cell disease (SCD) (introduced in Illinois in 1989) and cystic fibrosis (CF) (introduced in Illinois in 2008). NBS for both these autosomal recessive genetic conditions reveals some information about heterozygote carriers. We examined maternal attitudes and knowledge about NBS for SCD and CF, about the genetics, symptoms and treatments for SCD and CF, and how women learn about NBS. We hypothesized that there would be greater knowledge of SCD than CF; and that most women would be unfamiliar with specific details about NBS, but that they would be supportive of NBS.

METHODS

We interviewed women in the post-partum unit of the University of Chicago Hospitals whose infants were admitted to the general care nursery. Interviews (conducted by CL and AS) took place Monday to Friday over 17 consecutive weeks (June-October 2008). Women who were less than 18 years old, were non-English speaking, or had DCFS (Department of Child and Family Services) involvement were not approached. Women were also excluded if the obstetricians, pediatricians, or social workers indicated they were inappropriate for inclusion. At initial contact, women were read a brief description of the study and offered a $5 incentive for participation. They were offered an opportunity to participate immediately or at another time prior to discharge. Those that were not interested were not recontacted. Oral consent was obtained prior to participation. In order to maximize uptake, interviews were conducted whenever the women were available, even if the child had not yet had blood taken for NBS.

The survey addressed knowledge of and attitude towards NBS, personal experience with genetic testing, and knowledge about the genetics, symptoms and treatments for SCD and CF. The questions about SCD were adopted from Adewuyi [2000] and a website sponsored by the Centers for Disease Control and Prevention (CDC) [2009]. Parallel questions were developed for CF.

If participants had never heard of SCD or CF they were not asked subsequent questions about those conditions. A separate section asked all participants their familiarity with and their perceptions of the severity of SCD and CF, using a 5 point Likert Scale (1=never heard of it to 5=very familiar and 1=not serious to 5=very serious, respectively). Participants had the option of saying they “did not know” how serious a condition was, and their response was excluded. Survey items were read aloud to all participants. Questions about carriers of SCD were phrased as “carriers of SCD” and repeated as “individuals with sickle cell trait (SCT)”. Throughout the survey, participants could ask for clarification of the questions but were not provided with correct answers for factual questions. If unsure of the answer to True/False questions, participants were encouraged to guess. If they refused to guess, the response was coded as “not sure” (<0.5% for each question). Demographics were also collected. At the conclusion of the survey, participants were offered some basic information about NBS, and the genetics, symptoms and treatments of SCD and CF. Participants were also given the opportunity to review the correct answers to knowledge questions and to ask questions about topics covered in the survey.

Descriptive statistics were performed. Responses to True/False knowledge questions were scored as correct or incorrect. A “not sure” was coded as incorrect. Percent correct (mean score) for all 20 questions was calculated. T-tests were performed comparing demographics against the mean scores with significance set at p<0.05. Because of the significant colinearity between 5 demographic variables (age, marital status, education, insurance statue, and race), linear regressions were conducted with mean scores as the dependent variable and the 5 demographics as independent variables. Statistics were performed using SPSS 16.0.

University of Chicago Institutional Review Board approved this project and allowed for oral consent and the waiver of written informed consent.

RESULTS

Of the 477 women who were in residence on interview days, 51 (11%) were not approached for study participation due to exclusion criteria: <18 years old, non-English speaking, DCFS involvement, or medical team/social work exclusions. Eleven (3%) women were approached but refused participation. Fifteen (4%) were approached and expressed interested in study participation but were discharged before being interviewed.

In total, 400 interviews were conducted. Of those, 12 were excluded (2 because they did not meet inclusion criteria, 1 was interrupted for patient care and not completed, and 9 were physicians). Physician-mothers were excluded after their responses were reviewed and were found to be significantly different from responses of the remaining lay participants (data not shown) and to be more similar to responses in a parallel survey of physician knowledge and attitudes towards NBS that was being conducted (Stark and Ross, manuscript under review).

Of the remaining 388 participants, the average age was 27±6 years and slightly more than 1/3 of participants (149/388, 38%) were first time mothers (Table I). Sixty-six percent (254/386) of participants were not married, 73% (282/386) were African-American, and 59% (220/374) had public health insurance. Less than 30% (114/387) had graduated college.

Table I
Demographics

Seventy-nine percent (307/387) of women had attended 10 or more prenatal visits, and only 5 (1%) did not receive any prenatal care. Data were not collected about the type of prenatal care provider (obstetrician versus midwife) nor whether the provider was affiliated with the University of Chicago. Thirty-eight percent of participants thought they had received some prenatal genetic testing (146/383) and 25% (97/383) were “not sure” if they had received prenatal genetic testing. Sixty-seven percent of participants had never heard of CF (260/388), compared to 4% (16/388) having never heard of SCD (p<0.05). Participants who had never heard of CF were more likely to be African American, younger than 27 years old, not a college graduate, not married and not privately insured (p<0.001 for each demographic variable, data not shown).

Among women who had heard of SCD or CF, more women reported having been tested for SCD (171/372, 46%) than for CF (42/128, 33%). Of the participants who had heard of SCD, 21% (79/372) of participants were aware of a family history of SCD or SCT (heterozygote for sickle cell disease) and 51% (191/372) knew someone with either SCD or SCT. Of the participants who had heard of CF, only 4% (5/128) were aware of a family history of CF or CF carrier and only 21% (27/128) knew someone with CF or a CF carrier. In total, 34 women self-identified as having SCT, 1 with SCD, and 1 as a CF carrier. Approximately one-third of the participants who were confident that “I am not a carrier” for SCD or CF report never having been tested for SCD (100/313 or 32%) or CF (36/99 or 36%) respectively.

Only 35% (133/378) of participants recalled their prenatal care provider mentioning NBS and slightly more than half (217/388, 56%) recalled NBS being mention by medical staff in the nursery. However, only 25% (97/388) of participants remembered ever having NBS explained to them. This low recall was true for both first-time mothers and women with more than one child. Sixteen women stated that they had learned about NBS from reading prenatal materials, often procured outside of the medical setting. Although 27% (104/388) of respondents thought they knew a condition included in the NBS blood spot; only 49 of the 104 (47%) correctly named one or more of the conditions. Although a few women (6/239, 3%) reported that their previous child(ren) had a positive NBS, upon further questioning, 2 of these women were referring to conditions that are not included in the NBS (jaundice or a heart condition), and 12 women who did not report having a child with a positive NBS, later mentioned having a child with SCT. Despite the small percentage who actually know what NBS tests for, nearly all women (321/388, 83%) think NBS is a good idea.

Average SCD knowledge score for the 96% of women who had heard of SCD was 66% and the average CF knowledge score for the 33% of women who had heard of CF was 63% (Table II). We found several important knowledge gaps. For example, many women thought that it was possible for carriers to develop the disease (60% for SCD; 52% for CF), or that carriers have a mild form of the disease (49% for SCD; 41% for CF). Similarly, the majority of women thought that a person with SCD (71%) or CF (68%) could transmit the disease to a child even if the partner was not a carrier. Most women thought that it was important to know if one was a carrier (96% for SCD; 91% for CF) because of potential health implications, but this is only true for SCT. Likewise most women thought there was no cure for either condition (78% for SCD; 80% for CF), although bone marrow transplant does exist as a cure for SCD.

Table II
Knowledge Questions

In bivariate analysis, 5 demographic variables correlated with higher knowledge scores for both SCD and CF: 1) being 27 or older; 2) being married, 3) having a college degree, 4) having private insurance, and 5) being non-African American (data not shown). Demographic variables were evaluated for colinearity using linear regression. Having a college degree remained significant for both SCD (72% vs. 65%, p<0.05) and CF (68% vs. 55%, p≤0.05). Being non-African American (70% vs. 55%, p<0.001) and having private insurance (68% vs. 51%, p<0.05) remained significant for CF knowledge but not for SCD knowledge.

There was more self-reported familiarity with SCD (3.32/5) than CF (1.97/5) (n=388, p<0.001), and both were perceived as being serious health conditions (4.25 for SCD and 4.17 for CF out of 5). Women who self-identified as being moderately or very familiar with SCD scored significantly better on SCD knowledge questions than those who self-identified as being less familiar (69% vs. 65%, p<0.001), but women who perceived SCD as serious or very serious were not more knowledgeable (67% vs. 65%). Women who self identified as being moderately or very familiar with CF and women who perceived CF as serious or very serious scored significantly better on CF knowledge questions (76% vs. 60% and 66% vs. 55% respectively, p<0.001 for both).

DISCUSSION

NBS is one of the most successful public health programs in preventing morbidity and mortality. Although the vast majority of our participants are very supportive of NBS, parental lack of awareness and understanding regarding the importance of follow-up testing and treatment threaten its success [Arn, 2007; James and Levy, 2006; Miller et al., 1990].

We found that virtually all women in our study had heard of SCD (96%) but that only a third of women (33%) had heard of CF. This may be due in part to the high percentage (74%) of African American women in our survey. SCD is more common in persons of African ancestry (one in 400–500 African Americans) [Smith et al., 2006]. However, a study published in 2005 from St Louis by Boyd et al. [2005] found that 69 of 231 (30%) African American women contacted to participate in a survey were excluded because they had not heard of SCD, whereas virtually all of our respondents (both African American and individuals of other ethnicities) were able to complete the SCD portion of the survey. In contrast, CF is more common in non-Hispanic Caucasians (one in 3300) and less common in other ethnic communities including African Americans (one in 15,300) [National Institutes of Health, 1999]. In our survey, the women who were able to complete the CF portion of our survey were more likely to be more highly educated or non-African American. The lack of familiarity with CF in the African American community needs to be rectified in order to ensure that African American children benefit from the therapeutic advances promised by early diagnosis of CF [Grosse et al. 2006].

One reason that our participants should have heard about SCD and CF is that all but 5 had received some prenatal care. The American College of Obstetrics and Gynecology (ACOG) recommends prenatal testing for sickle cell trait in individuals of African, Southeast Asian, and Mediterranean descent [ACOG Committee of Obstetrics, 2007]. ACOG also recommends routine prenatal screening for CF in Caucasian families and that all women be informed of, if not offered, prenatal testing for CF [ACOG Committee on Genetics, 2005]. Given that less than 40% of women reported receiving any prenatal genetic testing and a quarter were unsure whether they had received prenatal genetic testing, it seems that women are not being tested, are not being offered testing, or are not aware that prenatal testing was done. ACOG policy also recommends that obstetricians provide some basic information about NBS to all pregnant women [ACOG, 2007]. However, only 35% of our participants recalled any mention of NBS prenatally despite ACOG policy recommendations. While it may be that they were informed about NBS but did not recall the discussions, our data are consistent with previous studies that find that health care professionals are not discussing NBS with pregnant or post-partum women [Campbell and Ross, 2004; Faulkner et al., 2006; Larsson and Therrell, 2002].

Obstetricians are not the only health care providers failing to discuss, or at least failing to effectively discuss, NBS. Only 56% of the women recalled mention of NBS by medical staff in the post-partum period, and very few women could correctly name a condition included in the screening program despite the importance that the American Academy of Pediatrics (AAP) places on newborn screening as integral to the medical home [AAP Newborn Screening Task Force, 2000]. Data show that pediatric providers lack knowledge of NBS or take a passive approach, assuming that the public health department will ensure follow-up [Davis et al., 2006; Desposito and Lloyd-Puryear, 2001; Gennaccaro et al., 2005; Kemper et al., 2006]. The mandatory nature of NBS allows pediatric providers to avoid meaningful discussions of what NBS entails.

Overall knowledge of the two newborn screening conditions that we focused upon, CF and SCD, is poor. One explanation may be the lack of familiarity with both of these conditions (average scores were 3.32 for SCD and 1.97 for CF). Lack of familiarity may be explained by the lack of visibility of these conditions in the general population, [McClaren et al., 2008; Mitchell et al., 1993; Poppelaars et al., 2003; Treadwell et al., 2006; Watson et al., 1991] and the lack of public awareness of NBS programs more generally [Campbell and Ross, 2003; Davis et al., 2006; Detmar et al., 2007]. Less familiarity with CF may also be due to relative recent introduction of CF NBS in Illinois and the racial/ethnic composition of our patient population.

Despite the low familiarity with both SCD and CF, both conditions were perceived to be quite serious (SCD=4.25; CF=4.17). Gustafson et al. [2007] found that knowledge of SCD directly correlated with perceived severity of SCD. Although we did not find this correlation to be true for SCD, we did find this correlation with CF.

The most important factor to correlate with increased knowledge of SCD and CF was parental educational status. Greater efforts to promote genetic knowledge and health literacy earlier in the school years will be necessary to ensure greater understanding of NBS across all educational, socioeconomic, and ethnic communities. In addition alternatives to school-based programs should be developed including church-, clinic-, or community-based multi-media programs, [Sobel et al., 2009; Gason et al., 2004; Jeste et al., 2008]or home-based educational videos [Klandy et al., 2005; Paholpak et al., 2006; Rowley, 1989]

One limitation of our study was the racial/ethnic distribution (almost 3/4 were African American) which may have biased knowledge in favor of SCD and against CF given the relative frequency of these conditions in the African American community. The large majority of women had not heard of CF (n=260) whereas only 16 women had not heard of SCD. A second limitation is that maternal reports about what they were offered and told prenatally and postnatally is subject to recall bias. It may be that obstetricians and pediatricians discussed NBS more frequently than the women remember or that the terminology used in the clinical setting and in our survey were slightly different yielding more negative responses. We did not collect information about where or from whom participants received prenatal care, so we are not able to determine whether these providers have policies or practices in place to address NBS. We also interviewed post-partum women whenever it was convenient for them, and so in some cases their child had already had blood collected for NBS and at other times they had not. Although we did not specifically ask the women if the NBS blood spot had been collected or if they knew whether the NBS blood spot had been collected, both first-time mothers and women with previous children (who could have been aware of NBS from their earlier deliveries) expressed low awareness of NBS procedures and purpose. Our finding that limited information about NBS is communicated to pregnant and post-partum women is also consistent with other research studies that documented minimal conversations about NBS by both obstetricians and pediatricians [ACOG Committee on Genetics, 2005; Campbell and Ross, 2004; Faulkner et al., 2006; Larsson and Therrell, 2002].

CONCLUSIONS

NBS in Illinois includes mandatory screening for SCD and CF. In a sample of predominantly African American post-partum women, we found greater familiarity with SCD compared with CF. However there are significant knowledge gaps for both conditions. Post-partum women report inadequate education about NBS, but none-the-less, they are supportive of it. There are many missed opportunities to educate mothers about NBS in general and about specific conditions included in NBS panels in both the obstetric clinics and the nursery. Creative educational efforts are needed to promote health literacy in mothers of all educational backgrounds.

Acknowledgments

This research was funded in part by the Illinois Department of Public Health (Lang and Ross). Alex Stark was funded under the auspices of the Pritzker Summer Research Program which receives support from the University of Chicago Office of Medical Education and the National Institutes of Health.

The data were first presented as a poster at the 2009 American College of Medical Genetics Meeting, “Medical Genetics: Translating Genes into Health” Tampa Fl, March 2009: Colleen Walsh Lang, Kruti Acharya, and Lainie Friedman Ross, Maternal Knowledge & Attitudes about Newborn Screening for Sickle Cell Disease and Cystic Fibrosis. The data were also presented using the same poster at the Illinois Chapter of the American Academy of Pediatrics Annual 2009 Educational Conference Lisle IL, May 2009. Statistical help was provided by the Biostats Lab, a program funded in part by the University of Chicago Clinical and Translational Research Award (CTSA) of the National Center for Research Resources (NCRR).

References

  • Adewuyi JO. Knowledge of and Attitudes to Sickle Cell Disease and Sickle Carrier Screening among New Graduates of Nigerian Tertiary Educational Institutions. Nigerian Post Graduate Medical Journal. 2000;7:120–123. [PubMed]
  • American Academy of Pediatrics (AAP) Newborn Screening Task Force. Serving the family from birth to the medical home: A Blueprint for the Future – A Call for a National agenda on State Newborn Screening Programs. Pediatrics. 2000;106:389–422. [PubMed]
  • American College of Obstetrics and Gynecology (ACOG) ACOG Committee Opinion No. 393, December 2007. Newborn screening. Obstet Gynecol. 2007;110:1497–1500. [PubMed]
  • American College of Obstetrics and Gynecology (ACOG) Committee on Genetics. ACOG Committee Opinion. Number 325, December 2005. Update on carrier screening for cystic fibrosis. Obstet Gynecol. 2005;106:1465–1468. [PubMed]
  • American College of Obstetrics and Gynecology (ACOG) Committee on Obstetrics. ACOG Practice Bulletin No. 78: hemoglobinopathies in pregnancy. Obstet Gynecol. 2007;109:229–237. [PubMed]
  • Arn PH. Newborn screening: current status. Health Aff. 2007;26:559–566. [PubMed]
  • Boyd JH, Watkins AR, Price CL, Fleming F, DeBaun MR. Inadequate Community Knowledge about Sickle Cell Disease among African American Women. J Natl Med Assoc. 2005;97:62–67. [PMC free article] [PubMed]
  • Campbell ED, Ross LF. Parental attitudes regarding newborn screening of PKU and DMD. Am J Med Genet A. 2003;120A:209–214. [PubMed]
  • Campbell ED, Ross LF. Incorporating newborn screening into prenatal care. Am J Obstet Gynecol. 2004;190:876–877. [PubMed]
  • Center for Disease Control and Prevention (CDC) Sickle cell quiz. [Accessed April 10, 2009]. On the web at: http://www.cdc.gov/ncbddd/sicklecell/quiz/
  • Davis TC, Humiston SG, Arnold CL, Bocchini JA, Jr, Bass PF, 3rd, Kennen EM, Bocchini A, Kyler P, Lloyd-Puryear M. Recommendations for effective newborn screening communication: results of focus groups with parents, providers, and experts. Pediatrics. 2006;117:S326–S340. [PubMed]
  • Desposito F, Lloyd-Puryear MA, Tonniges TF, Rhein F, Mann M. Survey of pediatrician practices in retrieving statewide authorized newborn screening results. Pediatrics. 2001;108:E22. [PubMed]
  • Detmar S, Hosli E, Dijkstra N, Nijsingh N, Rijnders M, Verweij M. Information and informed consent for neonatal screening: opinions and preferences of parents. Birth. 2007;34:238–244. [PubMed]
  • Faulkner LA, Feuchtbaum LB, Graham S, Bolstad JP, Cunningham GC. The newborn screening educational gap: what prenatal care providers do compared with what is expected. Am J Obstet Gynecol. 2006;194:131–137. [PubMed]
  • Gason AA, Aitken M, Delatycki MB, Sheffield E, Metcalfe SA. Multimedia messages in genetics: design, development, and evaluation of a computer-based instructional resource for secondary school students in a Tay Sachs disease carrier screening program. Genet Med. 2004;6:226–231. [PubMed]
  • Gennaccaro M, Waisbren SE, Marsden D. The knowledge gap in expanded newborn screening: survey results from paediatricians in Massachusetts. J Inherit Metab Dis. 2005;28:819–824. [PubMed]
  • Grosse SD, Rosenfeld M, Devine OJ, Lai HJ, Farrell PM. Potential impact of newborn screening for cystic fibrosis on child survival: a systematic review and analysis. J Pediatrics. 2006;149:362–366. [PubMed]
  • Gustafson SL, Getting EA, Watt-Morse M, Krishnamurti L. Health beliefs among African American women regarding genetic testing and counseling for sickle cell disease. Genet Med. 2007;9:303–309. [PubMed]
  • Guthrie R, Susi A. A simple phenylalanine method for detecting phenylketonuria in large populations of newborn infants. Pediatrics. 1963;32:338–343. [PubMed]
  • James PM, Levy HL. The clinical aspects of newborn screening: importance of newborn screening follow-up. Ment Retard Dev Disabil Res Rev. 2006;12:246–254. [PubMed]
  • Jeste DV, Dunn LB, Folsom DP, Zisook D. Multimedia educational aids for improving consumer knowledge about illness management and treatment decisions: a review of randomized controlled trials. J Psychiatr Res. 2008;42:1–21. [PubMed]
  • Kemper AR, Uren RL, Moseley KL, Clark SJ. Primary care physicians’ attitudes regarding follow-up care for children with positive newborn screening results. Pediatrics. 2006;118:1836–1841. [PubMed]
  • Kladny B, Gettig EA, Krishnamurti L. Systematic follow-up and case management of the abnormal newborn screen can improve acceptance of genetic counseling for sickle cell and other hemoglobinopathy trait. Genet Med. 2005;7:139–142. [PubMed]
  • Koch J. Robert Guthrie--The PKU Story: Crusade Against Mental Retardation. Carol Stream IL: Hope Publishing House; 1997. p. 214.
  • Larsson A, Therrell BL. Newborn screening: the role of the obstetrician. Clin Obstet Gynecol. 2002;45:697–710. [PubMed]
  • McClaren BJ, Delatycki MB, Collins V, Metcalfe SA, Aitken M. ‘It is not in my world’: an exploration of attitudes and influences associated with cystic fibrosis carrier screening. Eur J Hum Genet. 2008;16:435–444. [PubMed]
  • Miller ST, Stilerman TV, Rao SP, Abhyankar S, Brown AK. Newborn screening for sickle cell disease. When is an infant ‘lost to follow-up’? Am J Dis Child. 1990;144:1343–1345. [PubMed]
  • Mitchell J, Scriver CR, Clow CL, Kaplan F. What young people think and do when the option for cystic fibrosis carrier testing is available. J Med Genet. 1993;30:538–542. [PMC free article] [PubMed]
  • National Institutes of Health Consensus Development Conference. Genetic testing for cystic fibrosis. Archives Internal Med. 1999;159:1529–1539. [PubMed]
  • Paholpak S, Jetsrisuparb A, Wiangnon S, Sangsahachat D, Padtawara LO. Results of Video-Education on “Genetic Transmission in Thalassemia” to Thalassemic Patients and Their Parents. J Med Assoc Thai. 2006;89:1909–1914. [PubMed]
  • Poppelaars FA, van der Wal G, Braspenning JC, Cornel MC, Henneman L, Langendam MW, ten Kate LP. Possibilities and barriers in the implementation of a preconceptional screening programme for cystic fibrosis carriers: a focus group study. Public Health. 2003;117:396–403. [PubMed]
  • Rowley PT. Parental receptivity to neonatal sickle trait identification. Pediatrics. 1989;83:891–893. [PubMed]
  • Smith LA, Oyeku SO, Homer C, Zuckerman B. Sickle Cell Disease: A Question of Equity and Quality. Pediatrics. 2006;117:1763–1770. [PubMed]
  • Sobel RM, Paasche-Orlow MK, Waite KR, Ritter SS, Wilson EA, Wolf MS. Asthma 1-2-3: A Low Literacy Multimedia Tool to Educate African American Adults About Asthma. J Community Health. 2009. [Accessed July 2009]. [serial online]. http://www.springerlink.com/content/784952um876r7265/ [PubMed]
  • Treadwell MJ, McClough L, Vichinsky E. Using Qualitative and Quantitative Strategies to Evaluate Knowledge and Perceptions about Sickle Cell Disease and Sickle Cell Trait. J Nat Med Assoc. 2006;98:704–710. [PMC free article] [PubMed]
  • Watson EK, Williamson R, Chapple J. Attitudes to carrier screening for cystic fibrosis: a survey of health care professionals, relatives of sufferers and other members of the public. Br J Gen Pract. 1991;41:237–240. [PMC free article] [PubMed]