36 GIST (NOT VERBATIM) NUMERACY PREDICTS DIABETES MEDICATION ADHERENCE: A FUZZY-TRACE THEORY APPROACH

Friday, October 19, 2012
The Atrium (Hyatt Regency)
Poster Board # 36
Decision Psychology and Shared Decision Making (DEC)
Candidate for the Lee B. Lusted Student Prize Competition

Priscila G. Brust-Renck, M.A., Valerie Reyna, PhD and Allison Portenoy, Cornell University, Ithaca, NY

Purpose: To examine the relationship between understanding the meaning (i.e., gist) of complex numerical information (such as a drug regimen) and adherence to medication in diabetic adults.

Method: Diabetic adults (N=28; 57% female; 28% Minority; 10% Hispanic; mean age=21, SD=3.1) and non-diabetic adults (N=110; 66% female; 33% Minority; 2% Hispanic; mean age=19.8, SD=1.6) were surveyed anonymously.  Adherence was measured through the eight-item Morisky Medication Adherence Scale (MMAS).  Participants also responded to the Raven’s Advanced Progressive Matrices (APM; intelligence test), Diabetes Knowledge Questionnaire (DKQ), Diabetes Numeracy Test (DNT), a newly developed Diabetes Gist Numeracy Test (DNT-G), domain-general Objective Numeracy Scale (ONS), and another newly developed domain-general Gist Numeracy Scale (GNS).

Result: Adherence to diabetes medication (i.e., MMAS) was correlated with a domain-general gist-based understanding of numbers (i.e., Gist Numeracy Scale) as opposed to a domain-general verbatim numeracy measure (i.e., ONS).  In a principal component analysis, the model accounted for 75% of the variance with MMAS loading on the largest factor with subscales of GNS and with a Russian roulette problem that tests gist-based approaches to risk.  Moreover, gist numeracy in a domain-specific context (DNT-G) was also found to account for unique variance beyond intelligence (APM), beyond knowledge for the domain (DKQ), and beyond domain-specific verbatim numeracy (DNT).

Conclusion: This study introduces a new measure of numeracy grounded in fuzzy-trace theory that assesses gist-based understanding of numbers.  Consistent with fuzzy-trace theory, adherence to medication increased with both gist numeracy and gist-based approaches to risk.  These results are consistent with a theoretical mechanism in which understanding numerical information (i.e., numeracy), such as diabetes drug regimens, owes more to gist than to verbatim information processing.  In contrast to traditional verbatim approaches to adherence, these results suggest that medication adherence could be substantially improved by creating gist-enhanced interventions to assist in translating numerical diabetes drug regimens into digested meaningful instructions for the patient.