Outcome Expectancies, Health Information Seeking, and Cancer Beliefs Associated with Multivitamin/Mineral Use in a National Sample, HINTS-FDA 2015.

BACKGROUND

Dietary supplements, including multivitamins/minerals, are commonly reported by adults, yet little is known about multivitamin/mineral use in relation to information seeking, cancer-specific outcome expectancies, and cancer beliefs.

OBJECTIVE

To examine the relationship of heath information seeking, beliefs about cancer, and outcome expectancies with multivitamin/mineral use within a national sample.

DESIGN

A secondary analysis of data collected by The Health Information National Trends Survey (HINTS) and the US Food and Drug Administration (FDA) (HINTS-FDA 2015) was conducted. HINTS-FDA 2015 evaluated information seeking, beliefs about cancer, and health behaviors and was a self-administered, two-stage mail survey sent to a random sample of US postal addresses stratified by county smoking rates.

PARTICIPANTS

Adult household residents were invited to participate, resulting in a 33% response rate (n=3,738).

MAIN OUTCOME MEASURES

Participants self-reported use of multivitamin/mineral products.

STATISTICAL ANALYSES

Adjusting for covariates (demographics, single-ingredient and herbal supplement use) weighted stepwise binary logistic regression was used to examine correlates of self-reported multivitamin/mineral use.

RESULTS

Intake was associated with less than a high school education, having health insurance, and single-ingredient and herbal supplement use. Trust in health organizations (odds ratio [OR]=1.67, P<0.001) and the expectancy that cancer could be avoided with dietary supplements (OR=1.76, P<0.001) correlated with use. Agreement that supplements labeled as "anticarcinogenic" could treat (OR=3.07, P<0.001) or prevent cancer (OR=6.06, P<0.001) correlated with multivitamin/mineral use. Fatalistic beliefs (P<0.001) and negative information-seeking experiences (P<0.001) were associated with slightly lower odds of use.

CONCLUSIONS

Despite leading health organizations' discouragement of dietary supplements for cancer prevention, this study found that trust in health organizations and outcome expectancies were associated with multivitamin/mineral use. This divergence presents a need to explore how dietary supplement evidence based recommendations can be translated and disseminated for the public.