Knowledge and educational needs of individuals with the factor V Leiden mutation


Stephan Moll, CB 7035, UNC School of Medicine, Chapel Hill, NC 27599-7035, USA.
Tel.: +1 919 966 3311; fax: +1 919 966 7639; e-mail:


Summary. Background: Genetic testing for factor (F)V Leiden is widely performed in an effort to prevent thrombosis-related morbidity. The implications of a positive test for patients' health perception and the extent of patients' understanding of results are not known. Objectives: This study examined patient experience of genetic testing for FV Leiden. Patients and methods: The study was a cross-sectional, mailed survey of 110 patients who tested positive for the FV Leiden gene mutation at an academic medical center between 1995 and 2001. Patient knowledge about FV Leiden, satisfaction with available information, and psychosocial reactions to testing were assessed and the influence of demographic and clinical characteristics on outcome measured. Results: The magnitude of thrombosis risk associated with FV Leiden was incorrectly estimated by 79% of participants. Many patients (64%) stated that they had not been given much information about FV Leiden and 68% still had many questions. Most patients (53%) felt that their healthcare providers do not understand FV Leiden. Patients who had been seen by a hematologist or in a specialized thrombosis clinic were more knowledgeable and had less information need. Most patients (88%) were glad to know genetic test results, despite negative psychosocial implications such as increased worry (43%). Conclusions: Knowledge of genetic status increases awareness of thrombosis risk among patients, but magnitude of risk is often overestimated. Affected individuals indicate that there is a lack of available information about FV Leiden and that additional educational resources are needed.


No consensus exists as to which individuals to test for factor (F)V Leiden [1,2], primarily because available data do not clearly demonstrate that management should be altered based on test results. However, enthusiasm about the opportunity to find a genetic explanation for a patient's thrombosis, as well as the perception that knowledge of genetic status might lead to better treatment of patients and potentially prevent thrombosis in family members, has led to widespread testing. The FV Leiden genetic test is now one of the most commonly performed tests in US genetic laboratories [3].

While testing for genetic predisposition is typically performed with the intent of improving the medical care of patients, the genetic information obtained has implications beyond its use for clinical decision making. The present study examined patients' experience of genetic testing for FV Leiden by studying their knowledge, satisfaction with information received from healthcare providers, and the psychological consequences of testing. In addition, the current informational needs and resources used by this population were investigated. The identification of gaps in the existing system and exploration of patients' needs should lead to strategies to improve healthcare delivery to individuals found to have FV Leiden.



All individuals who tested positive for the FV Leiden gene mutation by polymerase chain reaction at the Genetics Laboratory, University of North Carolina, Chapel Hill (UNC-CH) between 7 September 1995 and 24 October 2001 were identified (n = 303). The physicians of individuals ≥18 years of age at the time of the study were asked for permission to send their patient(s) a study packet.

One hundred and seven patients were excluded: 52 because a physician could not be located; 41 because no subject address was available; 11 because they were <18 years old; two because they were deceased; and one because of mental retardation. The 196 eligible subjects were sent an introductory letter, response postcard, questionnaire and a postage-paid return envelope. Subjects were asked to complete and return the response postcard, regardless of desire to participate. The study was approved by the Institutional Review Board of UNC-CH.


Previous publications served as guides in questionnaire design [4–7], which was pretested on four non-UNC patients with FV Leiden. Modifications were made based on their suggestions. The five-page questionnaire contained 48 quantitative and qualitative questions:

  • 1Demographics and clinical history: 15 questions.
  • 2Knowledge: eight true/false questions based upon factual information [1], assessing individuals' knowledge of (a) the clinical implications and (b) genetics of FV Leiden.
  • 3Information satisfaction: six Likert-style questions based on a previously utilized tool [5].
  • 4Information needs and resources: two quantitative questions, assessing the information resources participants (a) utilized and (b) found to be most helpful in learning about FV Leiden; three open-ended questions eliciting individuals' attitudes regarding (a) who should be tested for FV Leiden, (b) what information should be given to individuals with FV Leiden, and (c) what questions are of greatest significance for individuals with FV Leiden.
  • 5Influence of FV Leiden on health perception and anxiety: five Likert-scale questions.
  • 6Genetic testing issues: one yes/no question, asking participants to indicate whether they were glad to know their mutation status; one open-ended question, as to who participants thought should be offered FV Leiden testing.

Data analysis

Frequencies for all discrete variables were obtained. χ2 and Fisher's exact tests were used to assess the influence of (a) age, (b) gender, (c) education, (d) time since diagnosis, (e) attendance at a thrombosis clinic, (f) seeing a hematologist, and (g) personal history of venous thromboembolism, on knowledge questions. Wilcoxon rank sums were used to examine the influence of the same variables on health perception and information satisfaction questions. Age, time since diagnosis, and education group were classified into dichotomous variables for data analysis (age = 18–45 years or > 45 years; time since diagnosis <2 years or ≥2 years; education group = did not complete college or completed college/advanced degree). SAS Statistical Analysis software (SAS Institute Inc., Cary, NC, USA) was used for the analysis of quantitative data. Qualitative data were grouped based on recurrent themes and tabulated using SAS software. Significance was reported with P < 0.05, two-tailed.


Of 196 packets, 43 were returned due to incorrect addresses. Of the remaining 153, 118 (77%) were completed and returned. One hundred and ten respondents (72%) chose to participate, eight declined participation, and 35 did not respond.

Patient population (Table 1)

Table 1.  Demographic and clinical characteristics of respondents
VariableStudy participants (n = 110)
n (%)
  • *

    FVL, Factor V Leiden. Percentages are rounded and may not add up to 100%.

Age, years
18–4037 (34)
41–6046 (42)
>6027 (24)
Female62 (56)
Male48 (44)
Caucasian101 (92)
Black2 (2)
Multiracial4 (4)
Other3 (3)
<High school9 (8)
Completed high school47 (43)
Completed college28 (25)
Advanced degree26 (24)
Income ($/ year)
<20 00015 (14)
20 001–40 00031 (28)
40 001–70 00019 (17)
>70 00041 (37)
No answer4 (4)
Perceived reason for FVL testing
History of venous thrombosis62 (56)
History of arterial thrombosis4 (4)
Family history of blood clot9 (8)
Family history of positive test10 (9)
OB/fertility workup5 (5)
Other9 (8)
Did not know why tested11 (10)
How long since diagnosis
<1 year16 (15)
1–2 years15 (14)
2–4 years31 (28)
>4 years33 (30)
Do not know14 (13)
No answer1 (0)
Who informed patient of test result
Primary care physician20 (18)
Hematologist49 (45)
OB/GYN5 (5)
Nobody14 (13)
Other18 (16)
Did not answer4 (4)
Recall giving consent
Yes, verbal41 (37)
Yes, written26 (24)
No22 (20)
Unsure21 (19)
History of venous thrombosis
Yes83 (75)
Participated in a thrombosis clinic
Yes25 (23)
Saw a hematologist
Yes49 (45)

Of the respondents (n = 110), 39% did not recall having given consent for testing. Thirteen percent were not aware that they had tested positive for FV Leiden and were excluded from subsequent data analysis.

Patient knowledge

Ninety-four percent of participants understood that FV Leiden increases a person's risk of developing blood clots (Table 2). Almost one-third (30%) of participants did not recognize that lifestyle changes, such as refraining from smoking and engaging in physical exercise, may reduce the negative impact of FV Leiden on their health. Ambiguity regarding the association between FV Leiden and pregnancy complications was expressed among study participants, as 44% were unclear about such a relationship. Participants of reproductive age (18–45 years) were more likely than older individuals to believe in such an association (54% and 28%, respectively).

Table 2.  Patient knowledge about factor V Leiden
(n = 96) n (%)
(n = 96) n (%)
(n = 96) n (%)
  1. * AG, Age group; ED, education; VTE, history of venous thromboembolism; HE, saw a hematologist. P < 0.05 with χ2 analysis; P < 0.01 with χ2 analysis. Percentages are rounded and may not add up to 100%.

Increases risk of blood clots90 (94)1 (1)5 (5) 
Lifestyle changes may reduce risk67 (70)10 (10)19 (20) 
Not associated with pregnancy complications38 (40)16 (17)42 (44)AG
70% lifetime risk of developing blood clot20 (21)30 (31)46 (48)VTE, HE
Affects equal number of males and females14 (15)23 (24)59 (61)AG, ED
DVT and PE most common complications68 (71)0 (0)28 (29)AG, VTE
Inheritance related to blood type35 (36)4 (4)57 (59) 
Risk to child to inherit is 50 : 5055 (57)10 (10)31 (32) 

Less than 50% of patients with FV Leiden will develop a venous thromboembolism in their lifetime [8]. When asked to respond to the statement ‘approximately 70% of individuals with FV Leiden will develop a blood clot in their lifetime’, only 21% of individuals recognized this risk estimate to be incorrect. Individuals who had seen a hematologist were more likely to respond correctly to this question, 28% vs. 8%. Uncertainty about magnitude of risk was particularly high (67%) among asymptomatic individuals. Forty-three percent of participants did not know that the chance is 50% to inherit FV Leiden from a heterozygous parent, and 85% did not realize that an equal number of males and females carry the FV Leiden mutation.

Patient satisfaction (Table 3)

Table 3.  Patient satisfaction with information about factor V Leiden
CharacteristicStrongly agree
(n = 96)
n (%)
Agree somewhat
(n = 96)
n (%)
(n = 96)
n (%)
Somewhat disagree
(n = 96)
n (%)
Strongly disagree
(n = 96)
n (%)
  • *

    AG, Age group; G, gender; ED, education; HE, saw a hematologist; NA, no answer; TC, participation in a thrombosis clinic.

  • P < 0.05 using Wilcoxon rank sum analysis;

  • P < 0.01 using Wilcoxon rank sum analysis. Percentages are rounded and may not add up to 100%.

Have been given much information11 (11)20 (21)4 (4)25 (26)36 (38)ED, TC, HE
Information from many people7 (7)22 (23)5 (5)19 (20)43 (45) 
Information is consistent23 (24)28 (29)20 (21)10 (10)15 (16) 
Confident in understanding8 (8)25 (26)14 (15)24 (25)25 (26) 
Still have many questions40 (42)25 (26)13 (14)12 (13)6 (6)AG,ED, TC
Healthcare providers understand18 (19)27 (28)18 (19)14 (15)19 (20)G

Almost two-thirds (64%) of participants stated that they had not been given much information. Individuals who were seen in a specialized thrombosis clinic staffed by physicians who specialize in coagulation disorders were more satisfied with the amount of information they received (62% vs. 22%). Seeing a hematologist was also predictive of information satisfaction, as 40% of individuals who had seen a hematologist were satisfied, compared with 19% of individuals who had not. Twenty-six percent reported that they received inconsistent information.

A minority (35%) of individuals felt confident in their understanding of FV Leiden. Sixty-eight percent of participants stated that they still had many questions about FV Leiden, especially individuals who had not completed college or were over the age of 45. Thirty-three percent of individuals who attended a thrombosis clinic were satisfied that their questions had been answered, compared with only 13% who did not receive care in this setting.

Only 47% of respondents felt that their healthcare providers had an understanding of FV Leiden. Males were more comfortable with their healthcare providers' knowledge than females (65% and 33%, respectively). Individuals diagnosed >2 years ago felt that their healthcare providers were less knowledgeable than those diagnosed more recently (42% vs. 19%; P = 0.06).

Information needs and current resources

In response to an open-ended question, participants most commonly communicated the need for more general information about FV Leiden, information pertaining to genetics, etiology of FV Leiden and testing of family members. Patients relied on their healthcare providers to obtain information about FV Leiden 77% of the time. The internet was used by 29% of respondents to obtain information and 50% of these individuals deemed the internet to be their most helpful resource. Resources provided by the medical profession had been utilized by only 6% of individuals.

Health perception

Twenty-eight percent of persons reported spending a significant amount of time trying to understand the health implications of FV Leiden. Reportedly, 51% had made positive lifestyle changes, including avoiding immobility, increasing exercise and altering dietary habits, due to genetic test results. Knowledge of FV Leiden status increased worry in 43% of individuals.

Genetic testing issues

Eighty-eight percent of respondents were glad to know their mutation status, 5% were indifferent and 7% wished that they did not have this knowledge. One individual reported disability insurance discrimination.


Available data do not clearly demonstrate that the management of individuals with or without thrombotic events should be altered based on the presence or absence of the FV Leiden mutation [2]. Thus, the primary benefit of testing lies in the opportunity to allow individuals and their families to identify, understand and sometimes control inherited health risks. Given that comprehensive, evidence-based guidelines for the management of individuals with FV Leiden are not yet available, it is recommended that benefits and hazards of various clinical options be discussed with patients, and their preferences considered in management decisions [9]. To be able to make well-balanced decisions on length and intensity of anticoagulant therapy, use of oral contraceptives or hormone replacement therapy, need for anticoagulation treatment during pregnancy, and genetic family testing in light of potential insurance discrimination, patients need to have adequate knowledge of the implications of a positive FV Leiden test.

The present study shows that a majority of individuals do not have adequate knowledge about FV Leiden. While almost all individuals (94%) know that FV Leiden increases the risk for thrombosis, many (79%) are unclear about the magnitude of that risk. Persons with a clinical history of thrombosis tend to overestimate risk, and asymptomatic individuals are often unclear about the likelihood that they will develop a thrombosis. Heightened risk perception is known to influence patient preferences regarding therapeutic interventions in other areas of healthcare [10]. In our study almost one-third of patients (30%) did not know that lifestyle changes, such as weight reduction or discontinuation of smoking, may reduce the negative impact of FV Leiden on their health. A higher appreciation of gene–environment interactions may result in health behavior changes and improved health outcome in patients at risk for thromboembolism. Our results of a lack of understanding of FV Leiden indicate a need for improved healthcare education of patients with thrombophilia.

Many individuals are aware of their lack of knowledge and have a need for more information. A minority (35%) felt confident in their understanding of FV Leiden and more than two-thirds (68%) still had questions. Fewer than half of the individuals (47%) felt comfortable with their healthcare providers' understanding of FV Leiden. Because FV Leiden was discovered only in 1994, and knowledge regarding its clinical implications has been acquired rapidly, physicians may indeed be unaware of its clinical significance. However, this was not assessed in this study. Further investigation to assess and possibly improve knowledge among healthcare professionals is warranted.

Specialized services may be beneficial to help educate patients about FV Leiden. Persons who are seen by a hematologist or in a thrombosis clinic are more satisfied with the quantity of information they receive and have fewer questions. Individuals seen by a hematologist are also more likely to estimate accurately thrombosis risk attributable to FV Leiden. Patient education materials may also help improve understanding. Only 6% of respondents used materials provided by the medical community to increase knowledge about FV Leiden. This indicates either a lack of materials, or the availability of resources that are of insufficient relevance to the patient. If developed, educational tools are likely to be used by this population, since 42% of individuals report researching FV Leiden independently to improve knowledge. Activities to increase the availability of materials could be achieved through a coordinated effort by the medical community or national patient advocacy groups. The internet may be a useful tool for dissemination of this information, since more than a quarter of patients report using this resource.

The adequacy of current consent protocols for FV Leiden testing may have to be assessed. More than one-third of patients (39%) did not remember having given consent for genetic testing. Since knowledge of FV Leiden status increased worry in 43% of individuals and resulted in at least one report of insurance discrimination, patients should be made aware of these possibilities prior to testing [9]. Lastly, it is noteworthy that 13% of patients in this study were unaware that they had the FV Leiden mutation. Whether this was due to insufficient communication of test results, or patient memory, was not assessed. In either case, this finding indicates that methods used to convey information from genetic testing need to be improved.

Response bias is a possible limitation of the study design, as those individuals who are more concerned about FV Leiden, or more interested in receiving information, may have returned the survey. Some patients in this cohort had ready access to a thrombosis clinic and many participants reported a high level of education. This had a positive impact on survey results regarding patient knowledge and patient need for further information. Knowledge of FV Leiden may generally be poorer among positive individuals than that represented by this cohort.

This study provides insights into the specific needs of patients with FV Leiden, on the basis of which changes in our healthcare delivery can be developed. Such improvements may include: obtaining written consent for genetic testing; better communication with patients to confer genetic test results; evaluation of healthcare provider training about FV Leiden; and better tools for educating patients, including specialized thrombosis clinics, printed materials and internet-based programs.


We are indebted to William Harrill for assistance in obtaining the sample population; to Judy Bean and Stacey Poe for help with data analysis; to Cindy Prows for contributions to the questionnaire design; to Kathleen Reed, Deb Smith and the members of the factor V Leiden support group (, who provided the inspiration for this project. This work was supported by an NIH career development award (BIRCWH; HD 01441-01; S.M.).