PREOPERATIVE INVESTIGATIONS IN ELECTIVE SURGERY : PRACTICES AND COSTS AT THE NATIONAL HOSPITAL OF SRI LANKA

Background: During preoperative preparation patients undergo in vestigations to detect asymptomatic diseases. The probability of finding significant ab normalities on such “routine” investigations is small, unnecessarily increasing costs of perioperat ive care. We evaluated current practices, compliance with guidelines and costs of preoperativ e in estigations at the National Hospital of Sri Lanka (NHSL).

Patients admitted to hospital for elective surgery commonly undergo a battery of "routine" preoperative investigations, often including a complete blood count, renal function tests, blood glucose level, urinalysis, chest x-ray (CXR) and an electrocardiogram (ECG).The goal of such investigations is to detect asymptomatic diseases not apparent on history and examination.If identified prior to surgery they could alter anaesthetic/surgical management.Appropriate treatment of these diseases helps to minimize perioperative morbidity and mortality. 1wever in the absence of any clinical indication, the probability of finding a significant abnormality on laboratory tests 2,3 , ECGs and CXRs 4,5 are small.Even among elderly patients "routine" preoperative testing was of little benefit. 6A randomized controlled trial of preoperative testing in cataract surgery revealed no differences in outcome between those subjected to and not subjected to routine testing. 7utine use of large number of screening tests increases the costs of perioperative care. 8nnecessary testing may cause harm to the patient due to over treatment for borderline/false-positive results.Hence the indiscriminate use of such investigations remains a matter for discussion, since costs may be increased without reducing perioperative complications. 9rious agencies including National Institute of Health and Clinical Excellence(NICE-UK) 10 and Canadian Anesthesiologists' Society(CAS) 11 have published guidelines to rationalize testing practice and reduce costs.To our knowledge there are no published studies evaluating preoperative testing practices and costs involved in Sri Lanka.The primary objective of this study was to understand current practices of preoperative testing and determine if they were compliant with the NICE-UK guidelines on preoperative testing.Secondary objectives included: identification of the source of testing orders non-compliant with guidelines, evaluating factors influencing decisions and evaluation of excess costs incurred due to unnecessary preoperative investigation.

Study population
The study was conducted at the NHSL, a tertiary care unit with 3000 beds.Each surgical team comprises of a Consultant Surgeon, a Senior Registrar (SR), Registrars, Senior House Officers (SHOs) and House Officers (HOs).In addition a consultant anaesthesiologist is in charge of preoperative assessment at each unit under whom either a Medical Officer -Anaesthesia (MOanaesthesia) or a Registrar-Anaesthesia visits the respective ward for preoperative assessment.This prospective study was undertaken among all patients undergoing elective surgery at seven general surgical units of the NHSL for a period of one month from January-February 2009.Patients undergoing emergency surgery were excluded.

NICE-UK
guidelines on pre-operative investigation was the standard of assessment, developed by NICE in conjunction with the National Collaborating Centre for Acute Care in UK.Details of the evidence, method and the guidance can be found on their website. 10The guidelines take into account the complexity of the surgery, American Society of Anesthesiologists (ASA) status of the patient and the major comorbidity.For each test, a colour coded system highlights if test is indicated or not.These guidelines tailor the patient to the procedure using as much evidence as possible, while allowing sufficient leeway for clinical judgment.The recommendations for AST/ALT, blood grouping & cross-matching and 2D-Echo was obtained after an iterative consensus process among a panel of experts.Remaining investigations were evaluated according to NICE-UK guidelines.The price of each investigation was obtained from ten government and non-government institutions.NICE-UK guidelines recommend that urine dipstick analysis to be considered in all patients undergoing elective surgery, which is not routinely done in Sri Lanka due to financial constraints.However all patients on admission have a 'urine ward-test' to examine urine for glucose, protein and etc.This was taken as comparable to urine dipstick analysis.

Data Collection
Data were collected using an expert-validated pretested interviewer administered questionnaire designed following the NICE-UK guidelines and ASA classification of patients.Ward practices on preoperative evaluation were assessed using a separate self-administered questionnaire distributed among HOs of the surgical units, it also evaluated the HOs knowledge on preoperative evaluation using ten commonly encountered general surgical case-scenarios developed and assessed using NICE-UK guidelines.The HOs were asked to record the surgical grade, ASA grade and to select appropriate investigations from a list of ten investigations given for each case.Each correct surgical grade, ASA grade and investigation was given one mark.Thus total marks per questionnaire for surgical grades, ASA grades and investigations were 10, 10 and 100 respectively.Ethical approval was obtained from the Ethics Review Committee of NHSL.

Statistical analyses
Data were double entered and cross checked for consistency.Analysis was done using SPSS v14 (SPSS Inc.,Chicago,IL,USA).Categorical data were described as proportions.Continuous data were described using mean and standard deviation and compared using unpaired Student's t tests.A p value of < 0.05 was considered statistically significant.*Urine analysis and ABG which showed 100% adherence to guidelines is not included, § MO-Anaesthesia or Registrar-AnaesthesiaThe response rate for ward practices and HO knowledge questionnaire was 83.3% (20 out of 24 HOs).HOs based their decision on preoperative investigation either by past experience of similar patient, directives given by seniors or their clinical training.Utilization of guidelines was minimal.None of the HOs were aware about any published guideline on preoperative investigations.In most surgical units investigations requested by all members of the surgical/anaesthetist team were done (Table 4) HOs demonstrated insufficient knowledge on the prices of most investigations.The estimated price of investigations given by the HOs had a wider range and significantly different mean from the actual price.The HOs estimated prices were comparable to the actual price only for CXR, FBC, Urine analysis and 2D-Echo (

Discussion
Preoperative assessment is a key process in minimizing morbidity of surgery.Diagnostic studies should be used as an adjunct to findings obtained from a review of history and examination or ordered to ensure that clinically silent conditions which can influence perioperative outcome are detected.
Majority of our sample population were healthy patients undergoing intermediate grade surgical procedures.Junior members of the team with less experience were involved in planning investigations in most patients.Involvement of senior members of the team on planning investigations was minimal.When investigations were evaluated for adherence to guidelines, urine analysis and ABG were the only investigations with good adherence (70%-100% compliance).It is mandatory in Sri Lanka that all patients have urine analysis, while ABG was requested only in one patient during the study period, resulting in these investigations demonstrating a good compliance to guidelines.ECG, FBC, RFT and blood grouping demonstrated moderate adherence (40-69% compliance).All other investigations demonstrated poor adherence (<40% compliance) to guidelines.A substantial excess cost is incurred by the hospital for unnecessary preoperative testing.This study was limited to the general surgical units thus actual total expenditure incurred due to unnecessary investigations by the hospital could be substantially higher.
When evaluating the source of testing orders noncompliant with guidelines the HOs and MO-Anaesthesia/Registrar-Anaesthesia were responsible for nearly all such requests.Previous studies have demonstrated that selective ordering of preoperative investigations by specialist anesthesiologists reduces the number and cost of tests. 12Other contributory factors were minimal utilization of guidelines, lack of awareness and performing investigations requested by all members of the team without supervision.In addition the HOs who were responsible for planning preoperative investigations in most patients demonstrated a poor knowledge on planning preoperative investigations for model case scenarios and also showed lack of awareness about the prices of investigations.
The results suggest that unnecessary laboratory testing during preoperative preparation of patients is still common.A substantial excess cost is incurred due to this.There is ample opportunity to rationalize testing practice and decrease testingrelated costs without altering outcome.We recommend the following remedies; (1).Education of surgical and anaesthetic teams on current practices and resulting costs (2).Adoption of guidelines on preoperative investigations aiming to modify existing practices (3).Re-evaluation after adopting guidelines.