3.2 NIV adherence and effect
Comparisons between the DS and non-DS cohorts were made across a number of usage, functional and clinic outcome parameters (Figure 1). No significant difference was observed between cohorts in pressure or humidity (data not shown).
A significant difference was observed within the usage parameters between cohorts. The DS group showed significantly greater use compared with their non-DS equivalent, 78.95 ± 2.26% versus 72.11 ± 2.14% of all days used within one year (p=0.032). However, of the days used there was no significant difference in adequate usage on those nights, adequacy defined as greater than four hours. Both cohorts exhibited >50% of nights with usage greater than four hours, 54.30 ± 2.98% and 59.61 ± 2.31%, in the DS and non-DS cohorts, respectively. This data is reinforced by the parameter of average use per night, 4.85 ± 0.27 hours within the DS cohort versus 5.07 ± 0.23 hours in the non-DS group where again, no significant difference was observed between cohorts (p=0.543).
NIV efficacy data from home NIV devices was analysed. Those within the DS cohort had a significantly higher AHI measurement (5.72 ± 0.47) relative to their non-DS counterparts (4.42 ± 0.27), p=0.049. There was significantly greater system leak (41.00 ± 1.61L/min versus 36.52 ± 1.18L/min, p=0.022), as well as, percent time at excess leak (21.02 ± 2.10 versus 16.14 ± 1.29, p=0.038) of the NIV system in the DS cohort compared with non-DS, respectively.