Dear Program Director: Deciphering Letters of Recommendation.

Background: Letters of recommendation (LORs) are an important part of applications for residency and fellowship programs. Despite anecdotal use of a "code" in LORs, research on program director (PD) perceptions of the value of these documents is sparse.

Objective: We analyzed PD interpretations of LOR components and discriminated between perceived levels of applicant recommendations.

Methods: We conducted a cross-sectional, descriptive study of pediatrics residency and fellowship PDs. We developed a survey asking PDs to rate 3 aspects of LORs: 13 letter features, 10 applicant abilities, and 11 commonly used phrases, using a 5-point Likert scale. The 11 phrases were grouped using principal component analysis. Mean scores of components were analyzed with repeated-measures analysis of variance. Median Likert score differences between groups were analyzed with Mann-Whitney tests.

Results: Our survey had a 43% response rate (468 of 1079). "I give my highest recommendation" was rated the most positive phrase, while "showed improvement" was rated the most negative. Principal component analysis generated 3 groups of phrases with moderate to strong correlation with each other. The mean Likert score for each group from the PD rating was calculated. Positive phrases had a mean (SD) of 4.4 (0.4), neutral phrases 3.4 (0.5), and negative phrases 2.6 (0.6). There was a significant difference among all 3 pairs of mean scores (all < .001).

Conclusions: Commonly used phrases in LORs were interpreted consistently by PDs and influenced their impressions of candidates. Key elements of LORs include distinct phrases depicting different degrees of endorsement.