Predictive value of Altmetric score on citation rates and bibliometric impact.

BACKGROUND: Bibliometric and Altmetric analyses provide different perspectives regarding research impact. This study aimed to determine whether Altmetric score was associated with citation rate independent of established bibliometrics. METHODS: Citations related to a previous cohort of 100 most cited articles in surgery were collected and a 3-year interval citation gain calculated. Citation count, citation rate index, Altmetric score, 5-year impact factor, and Oxford Centre for Evidence-Based Medicine levels were used to estimate citation rate prospect. RESULTS: The median interval citation gain was 161 (i.q.r. 83-281); 74 and 62 articles had an increase in citation rate index (median increase 2.8 (i.q.r. -0.1 to 7.7)) and Altmetric score (median increase 3 (0-4)) respectively. Receiver operating characteristic (ROC) curve analysis revealed that citation rate index (area under the curve (AUC) 0.86, 95 per cent c.i. 0.79 to 0.93; P < 0.001) and Altmetric score (AUC 0.65, 0.55 to 0.76; P = 0.008) were associated with higher interval citation gain. An Altmetric score critical threshold of 2 or more was associated with a better interval citation gain when dichotomized at the interval citation gain median (odds ratio (OR) 4.94, 95 per cent c.i. 1.99 to 12.26; P = 0.001) or upper quartile (OR 4.13, 1.60 to 10.66; P = 0.003). Multivariable analysis revealed only citation rate index to be independently associated with interval citation gain when dichotomized at the median (OR 18.22, 6.70 to 49.55; P < 0.001) or upper quartile (OR 19.30, 4.23 to 88.15; P < 0.001). CONCLUSION: Citation rate index and Altmetric score appear to be important predictors of interval citation gain, and better at predicting future citations than the historical and established impact factor and Oxford Centre for Evidence-Based Medicine quality descriptors.