Importance:
Despite the global increase in the ageing population, increasing complications and poorer outcomes are associated with older patients undergoing spinal intervention. We believe this could be due to a lack of research targeted towards this population.
Objective:
The primary objective of this review is to determine how applicable the current spinal research is for the ageing population. Despite several studies looking into ageism, many have only determined whether studies had an explicitly stated upper age cut-off. This, however, does not translate to the applicability of a study. Secondary objectives include looking at factors associated with ageism such as explicitly stated upper age cut-offs and type of sponsorship.
Evidence Review:
Full-text articles from PubMed were screened with our inclusion criteria including RCTs from the top 7 spinal journals used by spinal research professionals. Data was extracted by 2 members of the research team, and discrepancies were resolved by adjudication. The number of applicable trials were calculated for each 5-year age category from 40 to 100 years old. Trials were considered applicable for that age category if 25% or more of the patients were of that age or older.
Findings:
186 studies were included with a total of 26,238 participants. Decreased applicability was found with increased age. At 40-years-old, approximately 98% of studies were applicable for an individual in that age category; at 60-years-old, approximately 42% of studies were applicable; and at 80-years old, less than 2% of studies were applicable. Trials with explicitly stated upper age cut-offs had younger participants than trials that did not. Interestingly, sponsorship did not affect the participant ages.
Conclusions/Relevance:
The corpus of RCTs in spinal journals provide almost no information to treat patients 75-years or older. Ageism goes beyond explicitly stated cut-offs and sponsorship. It exists at three levels - systemic exclusion, explicit exclusion, implicit inclusion. Age based exclusion is not something that can be addressed by individual researchers acting independently but requires a systemic response as it largely arises at a supra-trial level.