Association of Grit Scores With Treatment Adherence and Biomarkers in Patients With Type 2 Diabetes

This cohort study analyzes the association of grit scores with treatment adherence, as measured with a survey and biomarker levels, among patients with type 2 diabetes.


Introduction
One in 12 adults worldwide has diabetes. 1 Medical treatment can reduce diabetes-related complications, but adherence to treatment can be difficult. 2 The reasons for nonadherence are multifactorial. Social scientists have found that character skills-sometimes referred to as socioemotional, noncognitive, or soft skills-are an important factor in whether people succeed in long-term challenges. For instance, the concept of grit, which is defined as "perseverance and passion for long-term goals," 3 is associated with success in challenging domains and is independent of intelligence. This cohort study explores whether scores on the grit scale are associated with treatment adherence and biomarker levels in patients with type 2 diabetes.

Methods
The ethics committee of the National Institute of Medical Science and Nutrition Salvador Zubirán approved the study. The study participants provided written informed consent. The reporting of this study conforms to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline. 4 Between October 2017 and November 2018, surveys were conducted among patients with type 2 diabetes at the hospital of the National Institute of Medical Science and Nutrition Salvador Zubirán immediately before their scheduled medical consultation. The survey included 4 questions on selfreported adherence to treatment, diet, and exercise, as well as the Short Grit Scale (Grit-S), which is computed as the mean of 8 items in which patients rate their perseverance of effort and consistency of interest on a 5-point Likert scale. 5 Unlike patient-engagement metrics, the Grit-S does not include questions about a patient's knowledge of the disease or treatments and, therefore, is a priori independent of medical outcomes. Patient socioeconomic information and laboratory data from a few days before the scheduled medical consultation and survey date were obtained from hospital records.
Multivariable linear regression analysis of adherence, biomarkers, and Grit-S scores was performed both with and without adjustment for covariates, which included 7 categories of socioeconomic status (determined and coded by hospital social workers on the basis of patient information, such as household income, dwelling characteristics, and occupation of the primary income earner) and cubic polynomials for years of schooling and number of years with diabetes.
Analysis was performed using Stata statistical software version 15.0 (StataCorp), and the 95% confidence interval around estimates reflects 0.025 in each tail; 2-tailed P Յ .05 (t test) was considered statistically significant. were surveyed in person. The response rate was 100%. The patients had a mean (SD) of 10 (5) years of schooling (range, 0-26 years) and a mean (SD) of 17 (10) years with type 2 diabetes (range, 0-47 Author affiliations and article information are listed at the end of this article. years). The percentage of patients who adhered to treatment ranged between 48.5% and 72.3%, depending on the measure of adherence ( Table 1). Grit was associated with greater adherence in all measures. An increase of 1 SD in the Grit-S score was associated with an increase in adherence of 6.1% to 12.3%, depending on the measure analyzed (Table 1). Results were similar with multivariable adjustment.

Discussion
To our knowledge, this study is the first to analyze the association between patient Grit-S score, treatment adherence, and measures of disease control. Among patients with type 2 diabetes, grit was associated with greater treatment adherence and better glycemic and cholesterol control.
Because character skill scales used by social scientists can be routinely measured among patients as they start treatment, these findings suggest that programs aimed at increasing treatment adherence may optimally focus on patients who, on the basis of the scores in those scales, are likely to display low adherence. These findings also suggest the importance of soft skills in overcoming long-term