Measurement properties of the WHO Disability Assessment Schedule 2.0 for evaluating functional status after inpatient surgery

BACKGROUND

Expert recommendations propose the WHO Disability Assessment Schedule (WHODAS) 2.0 as a core outcome measure in surgical studies, yet data on its long-term measurement properties remain limited. These were evaluated in a secondary analysis of the Measurement of Exercise Tolerance before Surgery (METS) prospective cohort.

METHODS

Participants were adults (40 years of age or older) who underwent inpatient non-cardiac surgery. The 12-item WHODAS and EQ-5DTM-3L questionnaires were administered preoperatively (in person) and 1 year postoperatively (by telephone). Responsiveness was characterized using standardized response means (SRMs) and correlation coefficients between change scores. Construct validity was evaluated using correlation coefficients between 1-year scores and comparisons of WHODAS scores across clinically relevant subgroups.

RESULTS

The analysis included 546 patients. There was moderate correlation between changes in WHODAS and various EQ-5DTM subscales. The strongest correlation was between changes in WHODAS and changes in the functional domains of the EQ-5D-3L-for example, mobility (Spearman's rho 0.40, 95 per cent confidence interval [c.i.] 0.32 to 0.48) and usual activities (rho 0.45, 95 per cent c.i. 0.30 to 0.52). When compared across quartiles of EQ-5D index change, median WHODAS scores followed expected patterns of change. In subgroups with expected functional status changes, the WHODAS SRMs ranged from 'small' to 'large' in the expected directions of change. At 1 year, the WHODAS demonstrated convergence with the EQ-5D-3L functional domains, and good discrimination between patients with expected differences in functional status.

CONCLUSION

The WHODAS questionnaire has construct validity and responsiveness as a measure of functional status at 1 year after major surgery.

A Randomised Controlled Trial of Pharmacist Medication Histories and Supplementary Prescribing on Medication Errors in Postoperative Medications

Errors in the management of regular medications at the time of hospital admission are common. This randomised controlled three-arm parallel-group trial examined the impact of pharmacist medication history taking and pharmacist supplementary prescribing on unintentional omissions of postoperative medications in a large perioperative service. Participants included elective surgical patients taking regular medications with a postoperative hospital stay of one night or more. Patients were randomly assigned, on admission, to usual care (n=120), a pharmacist medication history only (n=120) or pharmacist medication history and supplementary prescribing (n=120). A medication history involved the pharmacist interviewing the patient preoperatively and documenting a medication history in the medical record. In the supplementary prescribing group the patients’ regular medicines were also prescribed on the inpatient medication chart by the pharmacist, so that dosing could proceed as soon as possible after surgery without the need to wait for medical review. The estimate marginal mean number of missed doses during a patients hospital stay was 1.07 in the pharmacist supplementary prescribing group, which was significantly less than both the pharmacist history group (3.30) and the control group (3.21) (P <0.001). The number of medications charted at an incorrect dose or frequency was significantly reduced in the pharmacist history group and further reduced in the prescribing group (P <0.001). We conclude that many patients miss doses of regular medication during their hospital stay and preoperative medication history taking and supplementary prescribing by a pharmacist can reduce this.

Perioperative Mortality Risk Score using Pre- and Post-operative Risk Factors in Older Patients

We developed a risk score for 30-day postoperative mortality: the Perioperative Mortality risk score. We used a derivation cohort from a previous study of surgical patients aged 70 years or more at three large metropolitan teaching hospitals, using the significant risk factors for 30-day mortality from multivariate analysis. We summed the risk score for each of six factors creating an overall Perioperative Mortality score. We included 1012 patients and the 30-day mortality was 6%.

The three preoperative factors and risk scores were (“three A's”): 1) age, years: 70 to 79=1, 80 to 89=3, 90+=6; 2) ASA physical status: ASA I or II=0, ASA III=3, ASA IV=6, ASA V=15; and 3) preoperative albumin <30 g/l=2.5.

The three postoperative factors and risk scores were (“three I's”) 1) unplanned intensive care unit admission =4.0; 2) systemic inflammation =3; and 3) acute renal impairment=2.5. Scores and mortality were: <5=1%, 5 to 9.5=7% and ≥10=26%.

We also used a preliminary validation cohort of 256 patients from a regional hospital. The area under the receiver operating characteristic curve (C-statistic) for the derivation cohort was 0.80 (95% CI 0.74 to 0.86) similar to the validation C-statistic: 0.79 (95% CI 0.70 to 0.88), P=0.88. The Hosmer-Lemeshow test (P=0.35) indicated good calibration in the validation cohort. The Perioperative Mortality score is straightforward and may assist progressive risk assessment and management during the perioperative period. Risk associated with surgical complexity and urgency could be added to this baseline patient factor Perioperative Mortality score.

Crisis management during anaesthesia: anaphylaxis and allergy

BACKGROUND

Anaphylactic and anaphylactoid reactions during anaesthesia are a major cause for concern for anaesthetists. However, as individual practitioners encounter such events so rarely, the rapidity with which the diagnosis is made and appropriate management instituted varies considerably.

OBJECTIVES

To examine the role of a previously described core algorithm "COVER ABCD-A SWIFT CHECK", supplemented by a specific sub-algorithm for anaphylaxis, in the management of severe allergic reactions occurring in association with anaesthesia.

METHODS

The potential performance of this structured approach for each of the relevant incidents among the first 4000 reported to the Australian Incident Monitoring Study (AIMS) was compared with the actual performance as reported by the anaesthetists involved.

RESULTS

There were 148 allergic reactions among the first 4000 incidents reported to AIMS. It was considered that, properly applied, the structured approach would have led to a quicker and/or better resolution of the problem in 30% of cases, and would not have caused harm had it been applied in all of them.

CONCLUSION

An increased awareness of the diverse clinical manifestations of allergy seen in anaesthetic practice, together with the adoption of a structured approach to management should improve and standardise the treatment and improve follow up of patients suspected of having suffered a significant allergic reaction under anaesthesia.

A multiple-hospital anaesthetic problem register: establishment of a regionally organized system for facilitated reporting of potentially recurring anaesthetic-related problems

A regionally organized system aiming to facilitate reporting and retrieval of information about potentially recurring anaesthetic-related problems has been established, covering 20 separate hospitals. Components of the system include a reporting package to facilitate use by anaesthetists in busy clinical practice; centralized clerical support; supervision by anaesthetists; reports and laminated cards supplied to the patient; and a permanently accessible database. A new classification system for difficulties in airway management has been developed as part of the system. After initial establishment, the system has been utilized by a broad cross-section of anaesthetists in the region. The first 350 reports are described. The reporting rate is approximately 0.3% of all anaesthetics given in the region. We believe the success of this system has been primarily due to features aiming to facilitate reporting, "local" ownership and supervision by clinical anaesthetists.

The use of "quality-adjusted life years" (QALYs) to evaluate treatment in intensive care

This study examines the feasibility of using Quality-Adjusted Life Years (QALYs) to assess patient outcome and the economic justification of treatment in an Intensive Care Unit (ICU). 248 patients were followed for three years after admission. Survival and quality of life for each patient was evaluated. Outcome for each patient was quantified in discounted Quality-Adjusted Life Years (dQALYs). The economic justification of treatment was evaluated by comparing the total and marginal cost per dQALY for this patient group with the published cost per QALY for other medical interventions. 150 patients were alive after three years. Quality of life for most longterm survivors was good. Patient outcome (QALYs) was greatest for asthma and trauma patients, and least for cardiogenic pulmonary oedema. The tentative estimated cost-effectiveness of treatment varied from AUD $297 per QALY for asthma to AUD $2323 per QALY for patients with pulmonary oedema. This compares favourably with many preventative and non-acute medical treatments. Although the methodology is developmental, the measurement of patient outcome using QALYs appears to be feasible in a general hospital ICU.