A comparison of conventional and retrospective measures of change in symptoms after elective surgery.

BACKGROUND: Measuring change is fundamental to evaluations, health services research and quality management. To date, the Gold-Standard is the prospective assessment of pre- to postoperative change. However, this is not always possible (e.g. in emergencies). Instead a retrospective approach to the measurement of change is one alternative of potential validity. In this study, the Gold-Standard 'conventional' method was compared with two variations of the retrospective approach: a perceived-change design (model A) and a design that featured observed follow-up minus baseline recall (model B). METHODS: In a prospective longitudinal observational study of 185 hernia patients and 130 laparoscopic cholecystectomy patients (T0: 7-8 days pre-operative; T1: 14 days post-operative and T2: 6 months post-operative) changes in symptoms (Hernia: 9 Items, Cholecystectomy: 8 Items) were assessed at the three time points by patients and the conventional method was compared to the two alternatives. Comparisons were made regarding the percentage of missing values per questionnaire item, correlation between conventional and retrospective measurements, and the degree to which retrospective measures either over- or underestimated changes and time-dependent effects. RESULTS: Single item missing values in model A were more frequent than in model B (e.g. Hernia repair at T1: model A: 23.5%, model B: 7.9%. In all items and at both postoperative points of measurement, correlation of change between the conventional method and model B was higher than between the conventional method and model A. For both models A and B, correlation with the change calculated with the conventional method was higher at T1 than at T2. Compared to the conventional model both models A and B also overestimated symptom-change (i.e. improvement) with similar frequency, but the overestimation was higher in model A than in model B. In both models, overestimation was lower at T1 than at T2 and lower after hernia repair than after cholecystectomy. CONCLUSIONS: The retrospective method of measuring change was associated with a larger improvement in symptoms than was the conventional method. Retrospective assessment of change results in a more optimistic evaluation of improvement by patients than does the conventional method (at least for hernia repair and laparoscopic cholecystectomy).

Assessing patient-reported outcomes of cholecystectomy in short-stay surgery.

BACKGROUND: The project aimed at testing the feasibility of a quality improvement system based on patient-reported outcomes in short-stay surgery for cholecystectomy. METHODS: In two centers for short-stay surgery, patients referred for laparoscopic cholecystectomy were surveyed between Aug 1999 and Jan 2002. Patients reported on health-related quality of life (SF-36), symptoms (gallstone symptom checklist, GSCL) and other indicators preoperatively (T0), 14 days (T1) and 6 months postoperatively (T2). The SF-36 subscales physical functioning, bodily pain, and role physical as well as the GSCL and treatment satisfaction at T2 were considered as main outcomes. The main outcomes were analyzed by generalized linear models with regard to predictors. RESULTS: At T0 a total of 205 patients were included. The response rate at T2 was 63.4% (74.6% females, 53.6 years of age). The GSCL score at T0 (29.4% preoperatively) fell slightly to 27.9% at T1 and decreased to 14.8% at T2 (T0-T2: p < 0.001). The SF-36 subscales showed a different course over time (decrease of health-related quality of life at T1 and large increase at T2). The level of satisfaction with the outcome of cholecystectomy was 82.3%. The patient-reported outcomes were mainly influenced by the preoperative level, age and self-reported postoperative complaints. CONCLUSION: The low response rate was mainly due to nondelivery of questionnaires at T1 during the regular postoperative visit by the operating physician. Though nonresponse occurs under conditions of routine care, meaningful information was gained, which should be used for quality improvement activities. Because the preoperative level is a major determinant of the postoperative health outcomes, the prospective pre-post measurement should be preferred if institutional comparisons are intended.

[Patient reported process and outcome indicators for clinical audit in short-stay surgery]. / Prozess- und ergebnis-orientiertes Qualitäts-management in der Kurzzeitchirurgie mit Patientenbefragungen.

BACKGROUND: Based on patient-reported process and outcome indicators of care, a system for quality improvement in short-stay surgery was developed for hernia repair and cholecystectomy. The study aimed to test the feasibility and validity of the system. METHODS: In two centres for short-stay surgery all patients referred for hernia repair or cholecystectomy were surveyed between August 1999 and January 2002 (T0: preoperative, T1: 14 days post-OP, T2: 6 months post-OP). At T0 and T1 survey instruments were given to patients in the participating centres, at T2 the survey instruments were mailed. Of 342 hernia patients and 250 cholecystolithiasis patients at T0, responses from only 54.1% (hernia) and 63.4% (cholecystolithiasis) were available at T2. Non-response predominantly occurred between T0 and T1. Patients reported on satisfaction with care (FKKP), health-related quality of life (HRQL; SF-36), disease-specific symptoms (symptom checklists), treatment satisfaction and other indicators. RESULTS: Satisfaction with care was quite high. The process indicator of the lowest satisfaction was the provision of competencies to deal with problems at home after discharge at home. At T2 21.1% (hernia) and 66.2% (cholecystolithiasis) reported no complications. Both symptom checklists reflect the positive postoperative course (effect size T0-T2: 1.16 and 0.75). From a T0 level lower than the German reference population (six of the eight SF-36 subscales) HRQL reaches or exceeds the population norms at T2. CONCLUSION: In general, both the proposed proceedings and the instrument were applicable and feasible. Patient-oriented quality indicators contain additional information on processes and outcomes of care. However, the participating centres were not fully prepared to spend the extra effort necessary to organise such a longitudinal survey. To decrease non-response between T0 and T1, survey instruments should be mailed at T1 (instead of handing them over to patients during their postoperative visit).