Aim of the study:
To analyze the existing interpersonal relationship (IR) patterns between family members and their elderly relatives during the decision-making process and institutionalization in a long-term care facility in Colombia.

Subject or material and methods:
An observational study based on case reports analyzed using the Core Conflictual Relationship Theme (CCRT-LU) method. A sample of 489 relationship episodes (REs) was analyzed, involving six members from nuclear families.

Results:
Most IR patterns positioned the elderly person as the primary object. Statistically significant differences were found across all relationship patterns categorized as harmonious or non-harmonious (p < 0.001). Family members’ desires showed a predominance of harmonious patterns; however, their responses, along with the elderly persons’ desires and responses, identified non-harmonious patterns. Some patterns revealed statistical differences when correlated with the family members' sociodemographic and living conditions.

Discussion:
From the family members’ desires, a harmonious relationship pattern was observed, emphasizing helping, supporting, protecting, and staying close. However, their responses often showed non-harmonious patterns marked by feelings of depression, disappointment, hopelessness, distress, and frustration. Regarding the elderly persons' desires, a non-harmonious relationship pattern emerged, reflecting a wish to die, feeling unwell, or dissatisfaction. Similarly, the elderly individuals' responses included behaviors such as being hostile, threatening, or intimidating.

Conclusions:
A non-harmonious relationship pattern was found in the process of institutionalization of the adduto mayor.