Strengths & Limitations
The researchers in many of the above studies have recognised the need for a global approach to the management of CS, with results being amalgamated from studies across multiple continents. It is worth noting, however, that the lack of multivariable analysis in some of these studies from the meta-analysis prevented independent predictors of ICD appropriate/inappropriate therapy to be elicited. As discussed earlier, there was little data available to reflect the wide-ranging consortium of patients that can be affected by CS, and as such further determine which ethnic groups may be at lesser or greater chance of appropriate or inappropriate therapies. Future studies should collect data that spans across a broad array of ethnic backgrounds to capture a true reflection of the disease. Another limitation common to several CS meta-analyses is the risk of data overlap. Patient identifying features had been removed due to lack of consent, and as such there will certainly be inaccuracies in results, particularly given the relatively small sample size. As well as this, the retrospective study design lends itself to objectively poor result quality. Finally, although previously discussed as an effective proxy in light of no better alternative, the use of “appropriate therapy” as a surrogate endpoint is not a true representation of SCD and is generally accepted to be an imperfect tool that likely over-estimates risk.