Coping With Side Effects: A Daily Diary Study in Women With Breast Cancer Living With Adjuvant Endocrine Therapy.

Objective: Adjuvant endocrine therapy (AET) is increasingly being prescribed for up to 10 years to people diagnosed with hormone receptor-positive breast cancer. AET intake is often accompanied by side effects that significantly impact the well-being of people. The way individuals cope with medication-related side effects might play a pivotal role in their emotional adaption.

Methods: This intensive-longitudinal study investigated the association between self-reported coping strategies (Brief COPE) and psychological well-being (Patient Health Questionnaire-4) among women undergoing AET. A multilevel factor analysis resulted in the identification of four coping factors, namely, problem-focused, support-focused, meaning-focused, and avoidance-focused coping. Daily coping efforts and experienced side effects were analyzed as predictors of psychological well-being using multilevel modeling.

Results: A total of 215 women (M = 56.5 ± 10.9 years) participated, resulting in a total of n = 2080 daily surveys (M = 9.67 ± 1.08). On average, women reported 3.7 ± 2.2 different side effects per day. Days characterized by an elevated frequency of side effects and increased burden were associated with diminished well-being. Using more problem- and meaning-focused strategies than usual to cope with side effects correlated positively with well-being. Conversely, employing more support- and avoidance-focused coping strategies than usual was linked to reduced psychological well-being. Exploratory analyses focusing on individual coping strategies provided nuanced insights into coping behaviors.

Conclusion: The present findings underscore the relationship between women's coping efforts concerning medication-related side effects during AET and their daily well-being. Psychosocial education (e.g., cognitive behavioral therapy) may offer valuable benefits for patients by helping them develop adaptive coping strategies to manage side effects.