In 1997, Dexter et al. (1) developed the Iowa Satisfaction with Anesthesia Scale (ISAS), an 11 item questionnaire, to measure patient satisfaction with monitored anesthesia care. When tested on patients undergoing a variety of outpatient procedures, this questionnaire produced total scores with good reliability and validity sufficient to allow comparisons between patient groups or even across individual patients. In an accompanying article in this journal (2), we demonstrated that the ISAS remained reliable and valid when applied to cataract patients undergoing monitored anesthesia care at a small community hospital. In this study, we report on the use of the ISAS as a means to discover what factors determined patient satisfaction during monitored cataract care. We measured patient satisfaction using the ISAS, obtained patient ratings of quality, and defined and measured patient characteristics and the incidence of adverse events. We evaluated whether patient demographics, processes of care, or adverse outcomes produced significant differences in patient ISAS scores and quality of experience ratings.
After obtaining institutional and ethics committee approval, we recruited all patients undergoing outpatient cataract surgery on 2 days each week between January and May 2003. Patients were recruited by a research assistant and written informed consent was obtained from all participants. All cataract surgery was conducted under topical local anesthesia administered by the ophthalmologist and monitored anesthesia care with IV sedation given by an anesthesiologist. No patient received peri-bulbar or retro-bulbar blocks in addition to topical anesthesia. The manner of sedation was chosen by each anesthesiologist.
Information on patient demographics, patient preferences for sedation, and patient ratings of the importance of the anesthesiologist (Appendix 1) was collected by a research assistant during a preoperative interview. At this interview, patients’ anxiety levels were measured on a visual analog scale (VAS) from 1 to 10; this was then stratified into 3 levels: 0–3 = low, 4–6 = moderate, 7–10 = high. Intraoperative sedation, vital signs, times of start and finish of anesthetic care, adverse events, and all medications given were recorded by the anesthesiologist. Postoperative vital signs, adverse events, and times of admission and discharge were drawn from the recovery room record.
Tachycardia, bradycardia, hypertension, and hypotension were defined as any change >30% of preoperative levels. Respiratory depression was defined as O2 saturation <92%; it was considered severe if the patient did not respond immediately to verbal stimuli. Intraoperative pain ratings were obtained from responses to ISAS item 9: “I felt pain during surgery”; any patient who agreed with this statement (i.e., item score 3 or less) was considered to have had intraoperative pain. Mild, moderate, or severe postoperative pain was drawn from the recovery room nursing record: mild pain = complaints of discomfort not requiring any pain medications; moderate postoperative pain requiring oral pain medications; severe pain requiring IV medications (the IV was not removed until the patient’s condition was stable).
A written postoperative questionnaire, consisting of the ISAS and five additional ratings, was administered to patients in the recovery area (Appendix 1). All responses for the ISAS were scored from +1 to +6 (scores of negatively worded items were reversed). The final score is reported as the mean score of all 11 items (maximal score = 6). The additional postoperative patient ratings (Appendix 1) were: an evaluation of the quality of their intraoperative care on a scale of 1 to 6; any suggestions to make their care better; preference for more, the same, less, or no sedation if they were to have the operation again; and the degree of agreement to the statement, “There is nothing I would change in the care I just received.” Finally, we asked patients to rate the importance of the anesthesiologist again postoperatively using the same question as in the preoperative interview.
A sample size of 300 was chosen to allow multivariable regression analysis (3,4). We also based our sample size on the reported standard deviation of the ISAS of 0.87 (ó = 0.09) (1). A sample size of 300 allowed the ISAS score determined for all cataract patients to have 95% confidence limit interval of 0.02.
All scores on ISAS and patient ratings were reported as means (standard deviation). We tested the difference between mean ISAS scores of patients using unpaired Student’s t-test or analysis of variance where appropriate. We used χ2 to test for significance in differences between categorical variables.
To evaluate determinants of satisfaction and quality, we conducted two multivariable logistic regression analyses. In both models, we dichotomized the dependent variables according to the levels used in the validation study; this level also resulted in a sufficient number of patients in the “low” (satisfaction or quality) group for analysis. In the first model, the dependent variable was patient satisfaction. “High” satisfaction was defined as an ISAS score >5.4 of 6 (i.e., >90% satisfied); “low” were scores that were equal or <5.4. Factors that yielded significant differences in ISAS scores in a bivariate analysis were used as the independent variables.
For the second model, the dependent variable was patients’ rating of the quality of their experience. “High” quality was defined as a score of 6; low quality of care was defined as 5 or less. Independent variables were those factors showing significant differences in quality ratings in bivariate analyses. To minimize problems with multi-collinearity, in both models, we first ensured that the paired correlations between independent variables were not significantly correlated (r > 0.35) before entering them into the model. Final models included only variables that were significantly associated with the dependent variables. Goodness of fit was estimated using the Hosmer-Lemeshow statistic and P < 0.05 was used as the level of significance. All statistics were calculated using STATA 3.1.
Of 366 potential patients, 306 participated (94%). Thirty-eight were excluded because of language, communication difficulties, or mental illness, and 22 patients did not participate (12 felt too rushed; 10 refused). We obtained completed questionnaires from all remaining 306 participants (100% completion rate).
Mean patient age was 71.6 (sd = 9.8) yr and 56% were men (Table 1). Most patients were Canadian born, 70% spoke English, and 70% had at least a high school education. Ninety percent of patients were ASA physical status score II or III and 40% were undergoing cataract surgery on their second eye. Fifty-five percent of patients rated their preoperative anxiety levels as low, and most patients (66.7%) preferred only to be kept calm during surgery.
Surgeon 1 operated on 78% of patients; surgeon 2 on 22%. The duration of the surgical procedure was significantly shorter with surgeon 1 (9 min) than surgeon 2 (21 min). Patients were distributed relatively evenly among 4 anesthesiologists (17.3% to 29.7%); 1 anesthesiologist had only 3.6% of patients.
Virtually all patients (305 of 306) received midazolam in titrated amounts (range, 0.25–7 mg). More than 70% received fentanyl and 24% of patients received propofol. Remifentanil was used in <5% of patients (1 anesthesiologist). No patient received IV infusions of sedation.
Intraoperatively, the most common event was pain which occurred in 13.4% of patients (Table 2). Hypotension occurred in 4.9% of patients, mild respiratory depression in 3.9%, and bradycardia in 1.9%. Severe respiratory depression, arrhythmias, and coughing were the only other adverse events (<1%).
The most common postoperative adverse event was pain (Table 2). More than 37% of patients reported postoperative pain, 6% required no medications, and the remaining 94% were given oral pain medications (acetaminophen or acetaminophen and codeine). No patient had severe pain requiring IV medications. Significant cardiovascular changes occurred in <5% of patients. There was 1 occurrence each of dizziness, nausea, and vomiting (0.3%). More than 99% of patients arrived in the recovery area with an Aldrete recovery room score of at least 9 of 10. The recovery times (out of operating room to discharge home) was 37 min and was not significantly different among surgeons or anesthesiologists. No patient required admission to hospital.
The mean ISAS score was 5.6 (sd = 0.48); the median ISAS score was 5.7 (range: 3.3–6.0). Patients rated the quality of their experience as 5.1 (sd = 0.89); median 5 (range: 3–6). Among patients, 92% strongly agreed that “there is nothing I would change in the care I just received” and 93% had no suggestions they could offer about their care. Eight percent would have preferred more sedation; only 1 patient (0.3%) wanted no sedation. More patients indicated that the anesthesiologist was very important or important postoperatively (87.6%) than preoperatively (69.9%); only 5% of patients thought that the anesthesiologist was “not at all important” compared with 11% of patients preoperatively.
Younger patients (<60 yr of age) had significantly lower mean ISAS scores (P = 0.005) (Table 3). Patients whose income was between $60,000 and $90,000 had significantly lower ISAS scores (P = 0.008). Those who had higher preoperative anxiety levels had lower ISAS scores (P < 0.001). Sex, ASA physical status score, country of birth, education, and language had no impact on ISAS scores. There was a significant difference in ISAS scores between the patients of surgeon 1 and 2 (P < 0.0001) (Table 4). There were also lower ISAS scores for patients who had intraoperative and postoperative pain (P < 0.0001). The anesthesiologist, amount or type of intraoperative sedation, occurrence of intraoperative adverse events, and previous experience with eye surgery did not influence ISAS scores.
Seventy-six patients had “low” satisfaction (ISAS 5.4 or less). Two variables significant in bivariate analysis were not entered into the logistic regression model of low satisfaction: intraoperative pain (based on an item from the ISAS) and postoperative adverse events (too few patients to be included). Significant predictors of low satisfaction scores were postoperative pain (odds ratio [OR]: 4.84; 99% confidence interval [CI]: 2.21, 10.60), preoperative anxiety (OR: 1.17; 99% CI: 1.03, 1.34), and surgeon (OR: 0.21; 99% CI: 0.05, 0.91) (Table 5).
Sixty-nine patients rated the quality of their experience as low (5 or less). In bivariate analysis, factors that most predicted low quality of experience ratings were lower ISAS ratings, being male, having moderate or high preoperative anxiety, or having had any postoperative pain, or any other postoperative adverse event (Table 6). In the logistic model, only 2 factors emerged as significant predictors of a low rating of quality of experience: ISAS mean scores (OR = 0.28; 99% CI: 0.13, 0.59) and preoperative anxiety (OR = 1.12, 99% CI: 0.99, 1.28) (Table 7).
Overall, our findings support the safety and efficacy of monitored cataract care at a community hospital. Adverse events other than pain are uncommon and similar to rates reported in teaching hospitals (5,6). Patient satisfaction and ratings of quality were high despite the occurrence of perioperative pain. Multivariable logistic regression indicated that postoperative pain, surgeon, and preoperative anxiety were the most significant predictors of patients who were <90% satisfied. Patient satisfaction and preoperative anxiety were the most significant determinants of patient ratings of the quality of their experience.
The high level of patient satisfaction we found is similar to that reported by Dexter et al. (1) who found an 88% level of satisfaction in patients undergoing a variety of procedures under monitored care (53% of which were cataract surgery) and to the 96.5% of patients who reported that they were satisfied or very satisfied in a large survey of >19,000 patients after cataract surgery (7).
The determinants of patient satisfaction have been studied only after general anesthesia care. Females and younger patients have scored lower ratings of the quality of recovery from general anesthesia (8). In studies involving large numbers of patients undergoing general anesthesia, postoperative pain, nausea, vomiting, and grogginess or awareness are the major determinants of patient satisfaction with general anesthesia care (9–11). The association between high preoperative anxiety and lower satisfaction with care has not been previously reported in either general anesthesia or monitored care.
Three studies have reported on the incidence and extent of postoperative pain in cataract surgery under topical anesthesia. In their large series of 19,000 patients, Katz et al. (7) reported an incidence of “a little” pain in 4% and “a moderate or a lot” of pain in 1% but these rates were based on patient responses 1 week after surgery. Two studies reported that intraoperative or postoperative pain after topical anesthesia is usually mild (median score 1 on a VAS pain scale of 0–10) but not infrequent (occurring in 17%–19% of patients) (12,13). Our study confirms that pain during and especially after surgery may be more common than is appreciated by surgeons and anesthesiologists. Perhaps not surprisingly, postoperative pain was the most significant predictor of satisfaction with monitored anesthesia care.
Our study suggests that monitoring patient satisfaction and examining its determinants using the ISAS can be of value to cataract care providers. First, although significant adverse events are now infrequent in cataract surgery, relative dissatisfaction remains common and could be used as a means of tracking the consequences of changes in clinical care. Second, differences in factors that place patients at higher risk of dissatisfaction can be accounted and adjusted for in order for comparisons between patient satisfaction ratings (over time or between patient groups) to be fair and valid. Finally, understanding what reduces patient satisfaction can help focus quality improvement in cataract surgery.
For example, our study stimulated a review of surgical practices that could account for the differences in postoperative pain. This review revealed one important difference: the use of intraoperative pilocarpine drops (to contract the pupil at the end of the procedure) had remained a practice of surgeon 1 but not surgeon 2. Changing this practice has now reduced the use of pain medications by surgeon 1’s patients.
Our study has several limitations. First, the use of an interviewer to administer the questionnaire may introduce a positive bias in satisfaction scores (14). Questionnaire pretesting indicated that there would be substantial loss of data if the questionnaire were self-administered (because of the elderly age of our patients, limited vision in one or both eyes after surgery, and their underlying infirmity). We believe that the positive bias was minimal insofar as it did not affect the discriminatory capacity of the ISAS. Second, because postoperative adverse events and postoperative pain data were collected from the postoperative nursing record, it is possible that some events were missed. However, because any postoperative adverse event is unusual, we believe that the likelihood of missing significant events was small. Third, our findings may not be generalizable beyond the setting of cataract care at a community hospital. Determinants of patient satisfaction may also be different in larger (tertiary) cataract centers, or where dedicated anesthesia care providers are not used. Fourth, we did not examine other potential determinants of satisfaction, such as bedside manner, responsiveness to patient needs, and adequacy of information and education. Finally, our results can only be viewed as preliminary. Like all observational studies, our findings require corroboration by subsequent investigators.
If quality of care means meeting the needs of patients, then our findings provide support for the continued availability of sedation during cataract surgery. Although most patients report minimal preoperative anxiety and most only wish to remain calm and relaxed during surgery, it is noteworthy that 14% of patients had high ratings of anxiety and 11.9% wanted to be deeply asleep. Furthermore, 8% of patients would prefer more sedation if they were to have surgery again and the proportion of patients who rated the anesthesiologist as important in their care increased from 66% preoperatively to 88% postoperatively. Finally, until its surgical causes become clearer, minimizing perioperative pain may well require more sedation and more, not less, vigilance during cataract surgery.
In conclusion, our study indicates that patient satisfaction measured with the ISAS is a useful and valid indicator of the quality of cataract care at a community hospital. The most important determinants of low satisfaction identified in multivariable logistic regression were postoperative pain, surgeon, and preoperative anxiety. Examining the causes of lower patient satisfaction can focus anesthesiologists onto areas of care (such as monitoring and managing pain) that are most important to patient satisfaction and the quality of cataract care.
The authors acknowledge the support and assistance of the study anesthesiologists: Drs. Sean Travers, Rajalaxmi Wong, and Steven Bodley; the surgeons: Drs. Ken Kesty and Jon Spencer; and the nurses and support staff of the cataract clinic at the North Bay General Hospital.
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© 2005 International Anesthesia Research Society
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