Original Article
The Postoperative Morbidity Survey was validated and used to describe morbidity after major surgery

https://doi.org/10.1016/j.jclinepi.2006.12.003Get rights and content

Abstract

Objectives

To describe the reliability and validity of the Postoperative Morbidity Survey (POMS). To describe the level and pattern of short-term postoperative morbidity after major elective surgery using the POMS.

Study Design and Setting

This was a prospective cohort study of 439 adults undergoing major elective surgery in a UK teaching hospital. The POMS, an 18-item survey that address nine domains of postoperative morbidity, was recorded on postoperative days 3, 5, 8, and 15.

Results

Inter-rater reliability was perfect for 11/18 items (Kappa = 1.0), with Kappa = 0.94 for 6/18 items. A priori hypotheses that the POMS would discriminate between patients with known measures of morbidity risk, and predict length of stay were generally supported through observation of data trends, and there was statistically significant evidence of construct validity for all but the wound and neurological domains. POMS-defined morbidity was present in 325 of 433 patients (75.1%) remaining in hospital on postoperative day 3 after surgery, 231 of 407 patients (56.8%) on day 5, 138 of 299 patients (46.2%) on day 8, and 70 of 111 patients (63.1%) on day 15. Gastrointestinal (47.4%), infectious (46.5%), pain-related (40.3%), pulmonary (39.4%), and renal problems (33.3%) were the most common forms of morbidity.

Conclusion

The POMS is a reliable and valid survey of short-term postoperative morbidity in major elective surgery. Many patients remain in hospital without any morbidity as recorded by the POMS.

Introduction

Calls for increased clinical safety and accountability after high profile health care scandals, the drive to give patients a choice between different health care providers, and the linkage of funding to measured results have driven the outcomes reporting agenda forward. Cardiac surgery has led the way in the reporting of outcomes after surgery [1], [2], [3] and other surgical specialties are now following [4]. These initiatives are limited by the lack of validated instruments for describing the variety of outcomes occurring to individual patients. The measures currently used to assess outcome after surgery have significant limitations.

Mortality is the most commonly cited variable, but the low event rate after elective surgery limits its applicability as a general outcome measure. Length of hospital stay is known to be affected by medical and nonmedical factors and therefore functions as a hybrid measure of process and outcome [5], [6], [7], [8], [9]. Recording of perioperative morbidity has hitherto been limited: a recent systematic review of the measurement and monitoring of surgical adverse events found inconsistency in the quality of reporting of postoperative adverse events limiting accurate comparison of rates over time and between institutions [10]. A reliable and valid index of short-term postoperative morbidity would be of enormous value in quality of care, prognostic, and effectiveness research.

The Postoperative Morbidity Survey (POMS) is the only published prospective method for describing short-term morbidity after major surgery [11]. The POMS was designed with two guiding principles. First, it should only identify morbidity of a type and severity that could delay discharge from hospital. Second, the data collection process should be as simple as possible so that large numbers of patients can be routinely screened. Following on from these principles, a measure was produced that focused on easily collectable indicators of clinically important dysfunction in key organ systems. The indicators are obtainable from routinely available sources and do not require special investigations. These sources include observation charts, medication charts, patient notes, routine blood test results, and direct questioning and observation of the patient. Crucially, the indicators define morbidity in terms of clinically important consequences rather than traditional diagnostic categories.

Item generation was achieved through a three-stage process [11]. First, investigators collected information directly from patients, nurses, and doctors using open questions to identify reasons why the patients remained in hospital after surgery. Second, the responses obtained were categorized into domains of morbidity type. Thresholds were set for individual domains to achieve the primary goal of identifying morbidity of a type and severity that could delay discharge from hospital. Finally, the derived survey was reviewed and amended by an international consensus panel of anesthesiologists and surgeons. The POMS (Table 1) contains 18 items that address nine domains of postoperative morbidity. For each domain, either presence or absence of morbidity is recorded on the basis of objective criteria. The POMS is starting to be used in outcomes research [12] and in effectiveness research [13].

The aims of this study were to describe the level and pattern of short-term postoperative morbidity in a UK teaching hospital and to establish the reliability and validity of the POMS in patients undergoing elective major surgery.

Section snippets

Methods

All adult patients (aged 18 years or above) undergoing major elective surgery at the Middlesex NHS Hospital (London, UK) between July 1, 2001 and September 30, 2003 were eligible for inclusion in this prospective cohort study. Recruitment was interrupted during periods of study nurse annual leave.

Major elective surgery was defined as procedures expected to last more than 2 hours or with an anticipated blood loss greater than 500 mL. The following procedures were included: orthopedic surgery

Characteristics of study population

Of the 706 patients, 450 (63.7%) who were candidates for inclusion were enrolled into the study. The main reasons for nonenrollment were lack of preoperative consent (139 patients), communication problems (47 patients), and enrollment in other studies (37 patients). One of the enrolled patients withdrew after provision of consent, one was found to be participating in an interventional study, one was withdrawn by the attending consultant, and eight did not have surgery.

Patient and perioperative

Summary of findings

In this first use of the POMS in a UK setting, gastrointestinal, infectious, pain-related, pulmonary, and renal problems were the most common sources of morbidity after major surgery. Many patients remained in hospital despite having no morbidity, but no patient free of morbidity as defined by the POMS was found to have a morbidity-related reason for remaining in hospital: the POMS captured all relevant morbidity in inpatients. A variety of nonmedical reasons were identified as being

Conclusions

The POMS identified gastrointestinal, infectious, pain-related, pulmonary, and renal problems as the most common sources of morbidity after major surgery in a UK setting. Many patients remain in hospital despite absence of postoperative morbidity as defined by the POMS. Screening for postoperative morbidity using the POMS may be useful to identify patients remaining in acute hospital beds unnecessarily. The POMS may have utility as a tool for recording bed occupancy and for modeling bed

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