Out of 7,674 respondents available for analysis, 4,133 met inclusion criteria (age 50 or older and no history of cancer). For subjective numeracy, data from 3,286 respondents were analyzed after 847 (20.5%) were excluded because of missing data. For objective numeracy, data from 1,436 respondents were analyzed after 372 (20.6%) were excluded because of missing data. summarizes eligibility criteria and sample sizes according to missing data.
The association between respondent demographics and subjective and objective numeracy categories are summarized in . The mean age was 63.3 years, 45.9% were male, and 78.3% were White. Almost half (48.2%) had a high-school education or less and 25.0% reported annual incomes of less than $20,000. The majority (92.6%) had health insurance.
Demographics of Study Sample
Overall 39.4% of the sample answered “hard” or “very hard” on the subjective numeracy item and were classified as having low subjective numeracy. Nearly one fourth (22.6%) of respondents answered the objective numeracy item incorrectly and were classified as having low objective numeracy. Low subjective and objective numeracy were significantly associated with older age, non-White race, less educational attainment, and lower annual income. Respondents from the mail sub-sample who answered the objective numeracy question were more likely to report higher incomes than those of the total, composite sample; otherwise there were no significant differences in demographic characteristics between respondents that answered the subjective vs. objective numeracy item. There was a trend towards mail sub-sample respondents having higher subjective numeracy than phone sub-sample respondents (p=0.07).
Each of the perception of provider communication item responses were skewed towards a response of “always” in the total sample: 60% respondents reported always having the opportunity to ask all the health related questions they had, 46% reported their provider always paid enough attention to their feelings and emotions, 54% said their provider always involved them in decisions as much as they would like and 63% reported their provider always checked to make sure they understood the things they needed to do to take care of their health.
Multivariate logistic regression models examining the relationship between numeracy and perception of provider communication items are summarized in . In unadjusted analysis, low subjective numeracy was significantly associated with lower rates of reporting “always” for each communication item (OR 0.64-0.78). In a separate, unadjusted analysis, low objective numeracy was significantly associated with higher rates or reporting “always” for each communication item (OR 1.47-1.79). These associations persisted in the adjusted analysis for both low subjective numeracy (OR 0.62-0.72) and low objective numeracy (OR 1.54-1.71).
The Influence of Numeracy on the Perception of Patient-Provider Communication
In the adjusted model, demographic characteristics were not significantly associated with the communication items. An additional adjustment for sampling approach did not impact the association between subjective numeracy and perceptions of provider communication (not shown).
In unadjusted analyses, responses of “always” for perception of provider communication items were associated with higher CRC screening utilization for each item: health questions (OR 1.30, p = 0.004), attention to emotion (OR 1.20, p = 0.04), involved with decisions (OR 1.30, p = 0.003) and ensured understanding (OR 1.33, p = 0.002). Younger age, female gender, and an annual income of below $35k were significantly associated with a lower odds of reporting an up-to-date CRC screening test.
There were statistically significant interactions among subjective numeracy (hard/very hard vs. easy/very easy) and the communication items related to the perception that patients had a chance to ask providers questions (health questions) and the perception that providers paid attention to patient's emotions (attention to emotion) on CRC screening utilization (). The interaction between the health questions and attention to emotion items and subjective numeracy was such that a response of “always” for those two items offset the previously observed association between low subjective numeracy and less reported CRC screening. There were no statistically significant interactions among subjective numeracy and the communication items related to the perception that patients were involved in medical decisions (involved decisions) or that providers ensured understanding of medical issues (ensured understanding) on CRC screening. There was also no significant interaction between objective numeracy and any of the communication items on CRC screening utilization.
Effect of Perception of Patient-Provider Communication on the Association between Numeracy and CRC Screening (OR, Adjusted†, 95% CI and p-values for interaction between numeracy and communication)