Efficacy of daily hypertonic saline nasal irrigation among patients with sinusitis: A randomized controlled trial

Secondary outcomes were assessed with multiple methods. Compliance with nasal irrigation was recorded in a daily diary. The presence or absence of sinus symptoms (headache, congestion, facial pressure, facial pain, nasal discharge), antibiotic use, and nasal-spray use was assessed every 2 weeks. An exit questionnaire asked subjects to report categorically whether their sinus-related QOL had gotten worse, stayed the same, or improved, and to estimate the percentage of change (scale from 0 to ±100%). Overall satisfaction and side effects were reported at 6 months.

Statistical methods

Baseline characteristics of experimental and control groups were compared to assess randomization. Analysis, performed on an intention-to-treat basis, involved all 76 subjects randomized into the study. As dictated by the intention-to-treat model, the few missing values were imputed with multiple regression. Repeated measures analysis of variance contrasted the primary outcomes, that is, QOL status and sinus symptom scores within each group at baseline and subsequent periods. Differences between experimental and control groups were analyzed at each point in the repeated measures model and comprehensively for the entire time frame of the study. Statistical significance was assessed with 2-tailed tests. Data are presented as mean values with range of standard error, unless otherwise indicated.

Results

The study sample (Table 1) consisted of 76 subjects (55 female) randomized to experimental (n = 52) and control (n = 24) groups. Subjects’ ages ranged from 19 to 62 years, with a mean age of 42 years. Sixty-nine subjects (46 experimental and 23 control) completed the study. Seven subjects dropped out of the study at 1.5 months or earlier. A phone questionnaire was completed by 3 experimental dropouts; 2 of the 3 identified “lack of time” as the main reason for leaving the study; the remaining subject did not specify a reason. All 3 identified nasal irrigation as “helpful,” and none identified side effects as significant. The remaining 4 subjects were lost to follow-up. Dropouts tended to have slightly better baseline RSDI scores than nondropouts, 66.8 vs 58.1 points, but this difference was not significant (P = .15). No significant baseline differences were found between the groups of mostly white, female, well-educated subjects (Table 1). Baseline RSDI, SF-12, and SIA scores were similar in both groups. Although ENT subjects tended to have slightly worse baseline RSDI and SIA scores and improved slightly more during the study than other experimental subjects, the effect of clinic type (ENT vs primary care) was not statistically significant. By chance all subjects from ENT clinics (n = 6) and a disproportionate percentage of subjects with chronic sinusitis were randomized to the experimental group. Neither variable was statistically significant.

Experimental subjects showed a significant improvement in RSDI scores: 58.4 ± 2.0, 66.6 ± 2.2, 72.4 ± 2.2, and 72.8 ± 2.2 points at baseline, 1.5, 3, and 6 months, respectively (Table 2, Figure 2). Although the difference was not significant (P = .08), experimental subjects whose initial RSDI score was less than 50 points improved the most, with an average score change of 17.8 ± 4.4, and comparable control subjects had an average RSDI score change of 8.8 ± 2.9 points. Emotional and functional RSDI domains were not significantly related to score change; however, the physical domain of the survey was significant (P = .05).

SIA scores for experimental subjects improved (P < .05) at all follow-up points compared with control subjects; scores for the experimental group were 3.9 ± 0.1, 3.1 ± 0.2, 2.7 ± 0.2, and 2.4 ± 0.1 points at baseline, 1.5, 3, and 6 months, respectively (Table 2, Figure 2).

SF-12 score showed no significant differences between groups at any follow-up point but by 6 months trended toward significance (P = .06; Table 2).

Forty-one (93%) experimental subjects completing the exit questionnaire reported improvement. Most (n = 16, 73%) control subjects reported no change, but 18% reported worsening (P < .001; Table 3). Experimental subjects reported an average of 57 ± 4.5% improvement (range, 0–100%), whereas control subjects reported an average of 7 ± 5.9% worsening (range, -80% to 50%; P < .001).

Experimental subjects reported using nasal irrigation on 87% of days during the study; 31 subjects reported using nasal irrigation on 91% or more days, 13 subjects on 76% to 90% of days, and 5 subjects on 51% to 75% of days. Only 3 subjects used nasal irrigation on 50% or fewer days; these 3 subjects had relatively good baseline RSDI and SIA scores compared with other experimental subjects. Compliance was not significantly associated with changes in SIA or RSDI scores. The average survey completion rate was 96% at each assessment by each group.