In general, QOL improves after ESS

In general, patient-reported symptoms and QOL improve after ESS. One of the earliest studies was published by Kennedy in 1992, wherein 97% of 120 patients reported improvement in symptoms (85% marked improvement) after ESS with a mean follow-up of 18 months. A follow-up study on the same cohort showed these results to be durable up to 7.8 years after surgery. The development of validated, disease-specific QOL instruments in the mid 1990s added an additional layer of sophistication to ESS outcomes research. A recent literature review identified 45 articles published between 1966 and 2004 dedicated to the question of whether ESS leads to improvements in symptoms or QOL. In that report, all 45 studies demonstrated improvements in CRS-related symptoms and QOL, including 11 prospective studies and 5 that used validated QOL instruments.

Since that time, additional large prospective studies have been published using validated CRS-specific QOL instruments or symptom scales. Ling and Kountakis followed a cohort of 158 patients for 12 months after ESS, reporting statistically significant improvements in patient visual analog scale scores for Rhinosinusitis Task Force symptoms. Major Rhinosinusitis Task Force symptom scores ranged from 4.5 to 5.7 (0–10 point scale) at baseline and improved to 0.3 to 0.9 after ESS, representing a greater than 80% change from baseline. SNOT-22 scores were also shown to improve by 77% after surgery.

Bhattacharyya performed a similar study following 100 patients for an average of 19 months after ESS. RSDI symptoms were examined at preoperative and postoperative time points using Likert scales (0–5 range). After surgery, statistically significant decreases in major (facial pressure, nasal congestion, nasal obstruction, rhinorrhea, and hyposmia) and minor symptoms were noted ( P <.001 for all). The net change in major symptom score ranged from 1.5 to 2.3 points (0–5 range) with effect sizes noted to be large.

Recent studies have also focused on nonspecific symptoms, such as fatigue and bodily pain. Chester and coworkers performed a systematic review and meta-analysis of available studies looking at the effect of ESS on fatigue, vitality, energy, and malaise. All 28 identified studies described substantial improvement in fatigue following ESS. A similar study by the same author showed improvements in bodily pain scores as recorded by the SF-36 instrument.

One of the most comprehensive studies was published by Smith and colleagues in 2009. This multi-institutional study prospectively followed 302 patients at three medical centers for an average of 17.4 months after ESS. Mean scores improved on the RSDI by 18.9 points (15.8%; P <.001) and the CSS by 21.2 points (21.2%; P <.001). Among patients with poor baseline QOL, 71.7% experienced clinically significant improvement on the RSDI and 76.1% on the CSS.

The available literature provides a wealth of evidence demonstrating that CRS-specific symptoms and QOL improve after ESS to statistically significant levels; however, a “statistically significant” improvement may not necessarily translate into a clinically relevant change as perceived by the individual patient. One of the burdens of QOL research is to identify what has been called the “minimal clinically important difference” (MCID). The MCID is the minimal change in symptom or QOL after a given intervention that is perceptible and relevant to the individual patient. Establishing an MCID for a particular disease state and QOL instrument can be a difficult task. Until recently, little had been done to specifically define the MCID for CRS symptoms or CRS-specific QOL instruments. Instead, estimates of MCID were extrapolated from other disease states and used by proxy. For example, there has been much interest using visual analog scales for measuring pain in the operative and emergency department setting. Prior studies have shown the MCID for acute pain to be between 0.9 and 1.3 (10-point scale). Recent studies reporting scaled symptom scores by Ling and Kountakis, Bhattacharrya, and Smith and coworkers all easily reach this threshold of clinical relevance. Similarly, estimates of MCID exist for general QOL instruments, such as the SF-36, wherein 10 to 12.5 points (100-point scale) represents the minimum change believed to be clinically relevant for such diseases as asthma, chronic obstructive pulmonary disease, and coronary artery disease. Studies by Smith and coworkers and Kennedy evaluating long-term changes in SF-36 scores easily exceed these extrapolated thresholds.

The difficulty of defining an MCID is not unique to rhinologic QOL outcomes research. The most widely accepted solution in other disease states has been to use statistical constructs, such as standard error and standard deviation, to define the MCID. Generally speaking, QOL changes become clinically meaningful when they approximate half of the standard deviation of the baseline QOL value for the given population. This seemingly arbitrary definition of clinical relevance has been validated across many disease-specific and general QOL instruments. Considering the multi-institutional outcomes study by Smith and colleagues, this threshold of clinical significance was exceeded for both the disease-specific (CSS, RSDI) and general QOL improvements after ESS. Recently, attention has been given to defining the MCID for CRS-specific QOL instruments including the Rhinitis Quality of Life Questionnaire and SNOT-22. Table 1 shows the available published MCID values for CRS-specific QOL instruments.

Even with the beneficial outcomes seen after ESS, one must not confuse “improvement” with complete symptomatic resolution or “cure.” ESS is most typically reserved for patients who are refractory to standard medical treatments. The preponderance of the QOL studies show that these patients experience statistically and clinically significant improvement after ESS, but will likely still be left with some measurable burden of disease. For example, patients in the Bhattacharyya study showed average postoperative symptom scores ranging from 1 to 1.4 (0–5 scale). Table 2 shows symptom scores from a different cohort both before and after ESS. Similarly, the multi-institutional Smith and coworkers study reported average postoperative RSDI and CSS scores well above the norms for those without CRS. These studies were done at tertiary referral centers and usually include a disproportionate number of patients with severe phenotype and revision surgical status. As such, reported results might not be fully generalizable to all patients undergoing ESS.

Various clinical factors can influence QOL

Most patients perceive improvement in symptoms and QOL after ESS. There is variability, however, as to the degree with which any individual patient improves. Much attention has been given to identifying clinical factors that might enable treating physicians to predict a favorable or unfavorable outcome. Studies have looked at demographic factors (age, gender, ethnicity), medical comorbidities (asthma, allergies, aspirin (ASA) triad disease, depression, fibromyalgia, smoking, prior sinus surgery), and phenotypic qualities (polyposis, eosinophils) to identify characteristics that might allow outcome prediction. The results of these studies can at times seem conflicting given the subtle but important differences in study design and analysis, and the interrelatedness of various factors, which makes confounding difficult to fully eliminate.

Several factors have been shown to worsen baseline sinusitis-specific QOL, including ASA triad disease, depression, fibromyalgia, female gender, and nonwhite ethnicity. Patients with polyps and those of male gender have been shown to have slightly higher baseline QOL than the average CRS patient. Asthma, allergies, age, and revision surgical status seem to have little or no affect on baseline QOL. Regardless of their affect on baseline disease-specific QOL, few of the previously mentioned factors seem to influence the degree of improvement afforded by ESS. For example, patients with comorbid depression have worse disease-specific QOL scores at baseline and postoperatively compared with those without depression. They experience the same absolute level of improvement with ESS, however, as those without depression. At any one point in time a depressed patient has worse QOL than a nondepressed patient, but the absolute change in QOL after ESS is similar to those without depression. Similar results have been seen when closely examining patients with ASA triad disease, fibromyalgia, female gender, and nonwhite ethnicities. One recent study reported that a history of prior sinus surgery predicted less improvement in QOL after ESS. In that study, patients undergoing primary ESS were 2.1 times more likely to improve as patients undergoing revision surgery (95% confidence interval, 1.2–3.4; P <.006). No other factor was found to be similarly predictive by multivariate regression analysis.

Patients with nasal polyposis represent a unique clinical subgroup. The presence of nasal polyps naturally leads to worse objective disease severity as defined by imaging and endoscopic grading systems. Except for symptoms of nasal congestion, however, these patients seem to have a lighter burden of disease as measured by patient-centered symptom scores and QOL compared with patients without nasal polyps. Most clinicians have met the archetypal patient with polyps completely filling the nasal cavity yet relatively few complaints. Despite better preoperative QOL scores, patients with polyps tend to improve after ESS to a similar degree as those without polyps.

Recently, the authors reported the impact of mucosal eosinophilia on QOL outcomes in 102 patients with CRS. At the time of ESS, the degree of mucosal eosinophilia was quantified by microscopy. Although all patients demonstrated improvement after ESS, the subgroup of patients with mucosal eosinophilia greater than 10 eosinophils per high-powered field showed less improvement in disease-specific (CSS, RSDI) and general (SF-36) QOL than those without eosinophilia (<10 eosinophils per high-powered field) at an average follow-up of 16 months. Interestingly, patients without polyps but with mucosal eosinophilia performed the worst after ESS and patients without polyps or eosinophilia performed the best. The difference in outcomes between the groups clearly exceeded a threshold one would consider clinically relevant. Without pathologic review, these patients might otherwise be indistinguishable on clinical grounds alone. These findings are not unexpected and serve to support the commonly held clinical belief that patients with eosinophilic inflammation are especially difficult to treat.