Factors associated with early nonpersistence among patients experiencing side effects from a new medication

Abstract

Background: Drug discontinuation (i.e., nonpersistence) is often attributed to the emergence of adverse effects. However, it is not known whether other factors increase the risk of nonpersistence when adverse effects occur. Objectives: To identify factors associated with early nonpersistence among patients experiencing adverse effects from newly prescribed medications. Methods: A questionnaire was mailed to new users of antihypertensive, antihyperglycemic, and lipid-lowering medications in Saskatchewan, Canada, between 2019 and 2020. Only respondents experiencing adverse effects were included. Responses were compared between the nonpersistent group (i.e., people who had discontinued their medication) and the persistent group (i.e., those who were taking their medication at the time of the survey). Statistically significant factors were tested in multivariable logistic regression models. Odds ratios (ORs) and 95% CIs were reported. Results: Of the 3973 returned questionnaires, 813 respondents experienced adverse -effects from their new medication and were included in the study. Of these, 143 respondents (17.5%) had stopped their medication at the time of survey completion; most discontinuations (72.1%) occurred within 1 month of the first dose. Nonpersistent patients were older, had lower income, and were less likely to be taking an antihyperglycemic medication. After covariate adjustment, 6 factors were independently associated with nonpersistence: age less than 65 years (OR 1.56 [95% CI 1.01e2.41]), female sex (1.67 [1.08 e2.59]), health condition not considered dangerous (2.09 [1.25e3.51]), medication not considered important for health (6.90 [4.40e10.84]), failure to expect adverse effects before starting medication (2.67 [1.74e4.10]), and taking 2 or more medications (0.45 [0.27e0.73]). Conclusion: Despite the strong link between the emergence of adverse effects and early nonpersistence, our findings confirm that this association is highly influenced by several factors external to the physical experiences caused by the new medication.

Measuring the Influence of Side Effect Expectations, Beliefs, and Incident Side Effects on the Risk for Drug Discontinuation Among Individuals Starting New Medications, a Cross-sectional Study

“…The overall aim of the questionnaire was to capture adherence determinants that could be integrated with administrative databases to develop a comprehensive prediction model. 18 Saskatchewan has a universal drug insurance program that covers approximately 90% of the population of over one million residents regardless of age or socioeconomic status. All beneficiaries of the provincial drug insurance program were eligible to receive the questionnaire if they were at least 30 years old upon receiving a new claim for an antihypertensive, cholesterol-lowering, or antihyperglycemic medication between September 2019 and February 2020.…”

“…We previously found that negative medication beliefs were the most powerful predictors of early drug discontinuation among people experiencing side effects. 18 That is to say, patients with low confidence in their medication were more likely to discontinue it after a side effect occurred. Notably, expectations and beliefs can also influence the perception of side effects in addition to influencing the response to them.…”

Measuring the influence of expectations, beliefs, and medication side effects on the risk for drug discontinuation among individuals starting new medications

“…16 Briefly, the questionnaire contained 58 items designed to collect information on factors influencing adherence during the early phase of treatment including: patient-related factors (e.g., knowledge, attitudes, beliefs), social and economic factors (e.g., income, marital status), treatment-related factors (e.g., side effects), and health care system factors (e.g., appointment length, relationship/trust/support). 16…”

“…Higher scores represented greater support from a health care provider (Cronbach's alpha 0.82). 16 Also, a knowledge score was calculated from two questions asking if they knew what the medication was used for and the reasons why the medicine was good for them (Cronbach's alpha 0.77). 16 Both scores were dichotomized into binary variables as described previously.…”

“…We previously found that negative medication beliefs were the most powerful predictors of early drug discontinuation among people experiencing side effects. 16 That is to say, patients with low confidence in their medication were more likely to discontinue it after a side effect occurred. Notably, expectations and beliefs can also influence the perception of side effects in addition to influencing the response to them.…”