Fifty-two studies (n=291,417) were included in the review. Methodology scores ranged from 8 to 23. Twenty studies did not state loss to follow-up, 22 studies had no patients lost to follow-up and 11 studies had between two and 70 patients lost to follow-up.
There were conflicting results on mortality and morbidity being increased or unaffected by delayed surgery for prospective analyses that adjusted for confounding factors. One of three prospective studies that excluded unfit patients reported reduced mortality for early surgery compared with delayed surgery, but reported no effect on medical complications.
Two studies reported no difference for timing of surgery; one of these studies reported reduced medical complications and length of hospital stay for early surgery compared to delayed surgery and the other study reported reduced length of hospital stay for early surgery.
One of three prospective studies that included unfit patients reported reduced mortality for early surgery. Two studies reported no difference for timing of surgery for mortality. One study reported no difference for medical complications.
Mixed results were reported for prospective studies (12 studies) that had analyses unadjusted for confounding factors and retrospective studies (34 studies). For early surgery, reduced mortality was reported in 20 studies, two studies reported increased mortality and 21 studies reported no difference for timing of surgery. Eight studies reported reduced medical complications for early surgery, but seven studies reported no difference for timing of surgery.
Six studies reported reduced length of stay for early surgery, but there was no difference for 11 studies and no studies reported an increase for early surgery. Two studies reported a decrease in the likelihood of patients being able to return home for two studies. Two studies reported no difference for timing of surgery.