Table 1.

In simulating the modified approach we considered as "relevant" the citations that were retrieved in full text ("Level 1" screening in Figure 1).

Dataset	Total citations (N)	Retrieved in full text (% of N)	Included in the systematic review (% of N)
Proton Beam	4,751	243 (5.1)	23 (0.5)
COPD	1,606	196 (12.2)	104 (6.5)
Micro Nutrients	4,010	258 (6.4)	139 (3.5)

The Proton Beam dataset is from a systematic review of comparative studies on charged particle radiotherapy versus alternate interventions for cancers [32]. The COPD dataset is from a systematic review and meta-analysis of all genetic association studies in chronic obstructive pulmonary disease. The Micronutrients dataset is from a systematic empirical appraisal of reporting of systematic reviews on associations of micronutrients and disease [33]. Note the class imbalance in all three datasets.