Improved survival and 30-day mortality after gastrostomy in Scottish motor neurone disease patients: evidence from a national retrospective cohort study using STROBE criteria

Objectives: Defining historical changes and outcomes in the use of gastrostomy in the management of Scottish MND patients. Methods: The 1989-1998 and 2015-2016 Scottish national MND cohorts were used to examine the frequency, timing, and survival related to gastrostomy. The cohorts were censored for survival analysis. Results: There were 261 cases, 119 (46%) from the new register (2015-2016) and 142 (54%) from the old register (1989-1999). Percutaneous endoscopic gastrostomy (PEG) tubes were used exclusively in the old register vs. the new register where PEG (45%), Radiologically inserted gastrostomy (RIG) (44%) and a small number of peroral image-guided gastrostomy (PIGG) tubes (11%), p<0.01 were used. Odds of 30-d mortality in the old register were 2.8 times that in the new register, p<0.01. Median survival time from gastrostomy was significantly higher in the new register, 2.7 months, p<0.05. Median survival time from onset was also higher in the new register but non-significant, 3.2 months, p=0.30. Multivariate analysis identified age at onset (hazard ratio [HR] 1.02 p=0.01), time from onset to diagnosis (HR 0.74 p<0.01), subtype of onset (HR 1.52 p=0.01), with gastrostomy and Riluzole interacting as variables that predict risk of death. Conclusions: Gastrostomy use has increased with techniques changing over time. It is safer and survival time has increased post gastrostomy. Being older and diagnosed more quickly increases risk of death whilst taking Riluzole combined with gastrostomy reduced risk of death. Survival from onset has not significantly changed in Scottish MND patients having gastrostomy.