Older adults’ knowledge concerning risk factors for HIV transmission

Tags: foundation research, sexually transmitted disease, testing

Older adults’ knowledge concerning risk factors for HIV transmission

Sally P. Weaver, Ph.D., M.D.
McLennan County Medical Education and Research Foundation
Waco, Texas
Cindy Passmore, M.A.
Faculty Development Center
Waco, Texas


Approximately one-eighth of the U.S. population is 65 years of age or older and this proportion will likely double within the next 50 years. In general, adults over age 50 do not perceive themselves to be at risk for human immunodeficiency virus infection and acquired immune deficiency syndrome. However, HIV infection among people over age 50 has steadily increased over the last decade despite the U.S. trend of fewer infections in younger people.

Prior to 1995, 10 percent of new AIDS cases occurred in older adults, but this percentage grew to 14 percent by 1999.(1) Rates are even higher in states with higher geriatric populations, such as Florida. Today it is estimated that over 60,000 older Americans have AIDS and projections are much higher for HIV infection.(2) Many people with HIV are not aware of their status and this is likely for older Americans as well.(3)

Sexuality is important for older adults. Over 80 percent of people age 50 or older are involved in one or more sexual relationships.(4) Use of medications for erectile dysfunction has also increased sexual activity in older adults and may facilitate the spread of HIV infection and other sexually transmitted diseases.(5) Older adults who are at risk for HIV rarely use condoms, which have been shown to decrease HIV transmission rates.(6-8) Many older adults received blood transfusions or blood products between 1975 and 1984, a period when HIV was transmitted through donor blood products.(9, 10) Primary care doctors are less likely to discuss risky sexual behavior, drug use and other HIV transmission risk factors with their older patients.6 Additionally, older persons are significantly less likely to have ever been tested for HIV.(7)

Knowledge concerning HIV transmission, personal risks for infection and options for testing are often poor among older Americans.(8, 11-13) However, knowledge has the power to protect against infection in a population that is still at risk. The purpose of this study is to assess knowledge concerning HIV transmission among persons 50 years or older living in both nursing homes and in the central Texas community.


This study assessed knowledge of HIV transmission risks in people ages 50 and older in McLennan County, Texas, via a survey. The survey was administered in four nursing homes and at a community health fair in the fall of 2004. The population surveyed is approximately 50 percent Caucasian, 25 percent African-American and 25 percent Hispanic. People were eligible to participate if they were 50 years or older and were English speakers. Institutional review board approval was obtained through the McLennan County Medical Society Human Rights Committee.

The survey included basic demographic information such as age, gender, marital status, ethnicity, household income and educational level. Six true-or-false questions were asked concerning HIV transmission risks. The questions were stated as “Human immunodeficiency virus (HIV) infection may be caused by: 1) Blood transfusion prior to 1985; 2) Intravenous (IV) drug use; 3) Sexual contact with an HIV-infected person; 4) Sharing needles with an HIV-infected person; 5) Transfusion of blood clotting factors prior to 1985; 6) Sharing drinking glasses with an HIV-infected person.” A true response was the correct answer for all questions except number six. The total number of correct responses was calculated for each participant.

Demographic and other categorical data were summarized using frequency data. T-tests were used to establish statistically significant differences in mean responses to questions when the grouping variable (i.e. gender) had only two levels. Analysis of variance was used to establish statistically significant differences in mean number of correct responses to questions when the grouping variable (i.e. marital status) had more than two levels.


We received 449 completed surveys. The mean age of respondents was 72.8 years (SD 11.04). Seventy-five percent of subjects were female and 41.9 percent were married (Table 1). We were unable to determine ethnic mix of study participants as many of the oldest subjects stated they were Native American, although we surveyed no one belonging to this ethnic group.

Most participants verbally commented to the research staff their lack of knowledge concerning HIV. Both higher educational level (p<0.0001) and higher annual household income (p<0.0001) corresponded with a significantly higher percentage of correct responses to HIV knowledge questions. Married subjects scored significantly higher than single subjects (p=0.0028), but no better than divorced or widowed subjects. Subjects 65 years of age and older showed a non-significant trend of less correct responses to HIV knowledge questions (p=0.06).

Seventy-eight percent of subjects knew that a blood transfusion prior to 1985 was a risk factor for HIV (Table 2). One in five did not know that IV drug use or sharing needles puts a person at risk for HIV. Nearly 35 percent of subjects incorrectly thought that sharing drinking glasses is an HIV transmission risk factor.


Many subjects in our study could not correctly identify risk factors for HIV transmission and 35 percent incorrectly believed that the simple act of sharing a drinking glass may put them at risk for HIV. A 2000 Centers for Disease Control survey of HIV knowledge among all-age adults found similar results with 40 percent of respondents believing they could contract HIV through sharing a glass.(11) Hicks et al.(13) showed that older patients score much lower on HIV knowledge tests. Abel and Werner(8) found that people older than 45 had lower HIV knowledge scores and were at highest risk for HIV based on self reports of health behaviors such as not using condoms. Henderson(12) found that 65 percent of women age 50 and older have poor HIV knowledge and a high misperception of HIV transmission risk, with 63 percent believing HIV can be contracted through kissing.

Current and past HIV education and testing campaigns have largely overlooked older people although many members of this group are exposed to risk factors for HIV infection.(14) Apparently, HIV prevention education for older adults is still needed considering that many older adults remain sexually active.(4) Education about HIV risk factors is also needed as another common HIV transmission source for the older age group is their history of blood transfusions. Over 30 percent of women age 50 to 95 have received blood products between 1979 and 1985.(9) Of HIV/AIDS patients over 69 years old, 64 percent have received transfusions.(10)

Nearly 45 percent of American adults have been tested for HIV in their lifetime, but in persons 45 to 64 years old, less than 15 percent have been tested.(15) Primary care physicians are less likely to discuss HIV risk reduction or history of risky behaviors with patients over age 50,(6) but this practice needs to change. Regardless of patient age, family doctors should take a thorough history including a history of blood or blood product transfusions, IV drug use, sex with an IV drug user, men who have sex with men, sharing needles and known sexual contact with an HIV-infected person. The CDC recently revised guidelines for HIV testing and now recommends that all adults age 15 to 64 seen in health care settings be routinely tested for HIV.(16)

Limitations to this study include the fact that the survey was limited to a small geographic area that may not be representative of the entire country. Additionally, there was an over-representation of older adults in nursing homes and persons who may already be health-aware, since they were attending a senior health fair. This may actually have led to an over-sampling of older adults with more knowledge concerning HIV.

In conclusion, older Americans have relatively poor knowledge concerning risk factors for the transmission of HIV. They may be at higher risk for contracting HIV due to their lack of awareness, which may prevent them from protecting themselves against transmission of HIV. Family doctors need to be asking about risk factors in this population to assess risk and as an opportunity to educate patients regarding HIV transmission and how to protect against infection.



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This study was funded in part by a research grant from the Texas Academy of Family Physicians Foundation.