BACKGROUND: Neutropenia is associated with an increased risk of mortality and hospitalisation. Strategies, including the prescribing of colony-stimulating growth factors (CSFs), are adopted when a high risk (> 20%) of neutropenic complications are seen in the clinical trial setting. With a diverse treatment population that may differ from the patient groups recruited to studies, appropriate prescribing decisions by clinicians are essential. At present, results are conflicting from studies evaluating the risks of certain patient attributes on neutropenic events; we aimed to aggregate these associations to guide future management. DESIGN: A systematic review with a meta-analysis was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. Studies were identified through a literature search using MEDLINE, EMBASE and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases from inception to December 1, 2017. Studies were included into a meta-analysis if they adjusted for confounders; analyses were conducted in STATA v 15.1 SE. RESULTS: A total of 4415 articles were retrieved by the search with 37 meeting the inclusion criteria and 12 eligible for meta-analysis. Meta-analysis was conducted for increasing age and yielded a pooled odds ratio of 1.39 (1.11, 1.76, I = 24.1%), in our subgroup analysis of 4814 patients. Odds ratios for studies were pooled that reported associations for one co-morbidity compared to none and resulted in an overall odds of 1.54 (CI 1.09-2.09, I = 13.1%), including 9189 patients in total. CONCLUSIONS: Results can enhance current guidance in prescribing primary prophylaxis for treatments that either fall marginally under the internationally recognised 20% neutropenia risk.