A dozen ways to achieve more cost effective micro-biology.

Now that prospective payment has imposed limits on consumption of laboratory resources, inappropriate test utilization by clinicians can represent a serious dollar drain. Microbiology, one of the laboratory's least automated and most labor-intensive areas, is particularly liable to incur financial losses from excessive test ordering.

The main problem laboratories face is inappropriate utilization by clinicians. In the not too distant past, underutilization of the microbiology laboratory was common. A recent requirement by the Joint Commission on Accreditation of Hospitals for some form of audit of antibiotic usage has led most hospitals to require that appropriate cultures be taken, so underutilization is becoming less of a problem.

Clinical laboratory services are very susceptible to overutilization, however. Since hospitals will no longer be reimbursed for the cost of each laboratory test under prospective payment, excessive laboratory usage can very easily result in a significant loss of funds in many patient admissions.

An example of overuse is the ordering of differential counts. Shapiro et al analyzed the use of differential counts in a 700-bed university teaching hospital and found that 26 per cent of all differentials done in the hospital laboratory were unjustified. Forty-eight per cent came from medical services, 62 per cent from surgical services. The test results affected patient management in less than 3 per cent of patients, and no unjustified tests altered a patient's diagnosis or treatment. Elimination of unjustified differentials would permit a reduction in 1.8 FTEs from their hospital laboratory. It was concluded that the differential is overused and amenable to real cost reduction.

Because of the lack of automation presently available to the clinical microbiology laboratory, there is a direct relationship between the workload and the number of technologists needed. Technologists' salaries account for 50 to 70 per cent of a laboratory's microbiology is an expensive laboratory service. It has been noted that repetitive, often daily cultures from infected foci clearly reflect concern on the part of the physician but contribute little or nothing to patient care. Examples of this overuse include excessive numbers of blood cultures, daily sputum cultures from tracheostomized patients without evidence of pneumonia, daily cultures of drainage from infected foci, and Foley catheter tip cultures.

A study at one hospital revealed that the average patient had 6.1 bacteriology tests per admission. Some patients had as many as 122 bacteriology tests, including up to 24 urine cultures. A typical pulmonary patient in this study had an average of 16 sputum cultures, 13 blood cultures, and 9 urine cultures!

To promote the optimal use of laboratory tests, we must consider not only factors responsible for inappropriate or excessive use, but also those that foster underuse. The latter include failure to review test results and inability to interpret them. Optimizing laboratory utilization requires explicit criteria regarding when laboratory tests should be used and development of methods to insure that the resulting data are utilized properly.

To be appropriate, a test should affect a patient management decision. In microbiology, this primarily occurs through demonstration and identification of microorganisms and determination of their antibiotic susceptibilities.

The process usually involves genus identification and susceptibility testing and/or precise identification to species or subspecies level. For most physicians, the former has a greater priority than precise identification.

Besides providing information clinical requirements. Examples of this would include the typing of Haemophilus influenzae other than b, typing of Neisseria meningitidis and Klebsiella pneumoniae, and the species identification of yeast from mixed cultures.

Specimens of dubious value such as those from mouth lesions, bowel contents, perirectal abscesses, decubiti, vaginal discharges, and Foley catheter tips should not be processed. It is not clinically helpful to provide complete identification and antibiotic susceptibilities of more than three pathogens in a specimen. Recovery of three or more pathogens generally reflects contamination of the specimen with indigenous flora.

Concerned over the possible misuse of laboratory services, the state of Connecticut in 1975 formed an ad hoc committee of clinical microbiologists and pathologists to investigate the utilization of microbiology laboratories. Two years later, the College of American Pathologists convened a meeting in which infectious disease specialists, pediatricians, surgeons, and other physicians met with clinical microbiologists and pathologists to consider clinical relevance in microbiology.

The findings and recommendations of both meetings were strikingly similar. There was a recommendation that institutions establish a policy for controlling laboratory utilization.

Cost containment measures in medical practice will not be successful if they are initiated by administrative fiat. Conscientious physicians will rebel against constraints they see as deleterious to patient care. Demonstrating what is useful, as opposed to what is unnecessary or harmful, is the cornerstone of scientific medicine. While it is desirable that physicians know the sensitivity, specificity, and predictive values of laboratory tests, they cannot know the performance characteristics of all the tests they order. To minimize inefficient and ineffective practice, it is essential that clinicians and laboratory directors develop guidelines for testing.

The laboratory director should submit specific recommendations to the directors of the clinical services for their input. When agreement has been reached, the decisions should be approved by the medical board and incorporated into hospital policy by the administration. All attending physicians and the house staff should then be advised of the new laboratory policies and assured that appropriate exceptions can be made by consulting with the laboratory director. The active participation of the chiefs of service through chart review is also important for the success of cost containment programs.

Clinical laboratories can contribute further to improving the use of tests. Laboratory request forms need to be examined. Forms that list the entire inventory of available tests are an open invitation to the user to check off excessive numbers of tests. Active intervention to reinforce an educational program may be required to overcome established patterns of misuse of laboratory resources.

Specific strategies for cost containment include the following:

1. Have as much testing done as possible on an outpatient basis, preadmission and post-discharge. This reduces length of stay and removes some testing from prospective payment limits.

2. Revise laboratory request forms that list tests or procedures by check-off boxes. Provide a separate menu that lists specific tests. For example, when submitting female genital specimens, physicians should state whether they are for possible gonorrhea, vaginitis, surgical wound infection, or possible endometritis.

3. Attempt to shorten turnaround time through faster ways of getting the specimen to the laboratory, testing it, and delivering the results. Stat tests are disastrous from the perspective of laboratory efficiency and cost control, but are often necessary from a medical standpoint.

Many Stats can be avoided, however, by better routine scheduling and establishing priority of tests based upon clinical urgency. A procedure assigning priority to microbiology specimens based upon their relevance to the urgency of the clinical problem has been described by Ellner et al. Reorganize the laboratory into Stat and routine sections to improve productivity.

4. Eliminate tests that are unnecessry--i. e., that do not contribute to the patient's diagnosis, management, or prognosis. Typical examples of these are throat cultures for organisms other than beta hemolytic streptococci; identification of more than three pathogens in a specimen; cultures of oropharyngeal material, bowel contents, perirectal abscesses, decubiti, and Foley catheter tips, and anaerobic culture of surface wounds; and antibiotic susceptibility determinations on obvious contaminants, commensal species from sites they normally inhabit, or species with predictable susceptibilities.

5. Curb ordering of esoteric tests, and require the prior approval of an infectious disease specialist. An example is the culture of cerebrospinal fluid for acid-fast bacilli.

6. Eliminate replicate and redundant specimens by computer monitoring at registration. The laboratory cannot afford to perform three cultures on the same wound because an intern, a resident, and the attending physician all ordered one independently on the same day.

7. Eliminate tests done by standing orders or routine protocol. Typical examples are tracheal suction specimens from patients in the intensive care unit with no clinical evidence of pneumonia, and peritoneal dialysis specimens from patients with no signs of peritonitis.

8. Limit the maximum number of specimens of each type that will be accepted from a patient. Some suggestions are shown in Figure I.

9. Develop progressive test profiling, in which follow-up tests are automatically performed according to predetermined, cost-efficient algorithms designed to obtain the most diagnostic information. Examples are the testing of serum for syphilis, hepatitis, or streptococcal antibodies.

The laboratory can contribute to the more cost-effective use of antibiotics by selective reporting. In our institution, second-generation cephalosporin results are reported only if the organism is resistant to cefazolin, and third-generation drugs are reported only if the isolate is resistant to both cefoxitin and cefamandole.

10. Eliminate routine environmental cultures. These include samples from floors, surfaces, air, presterilized fluids, medications, or infant formula milk.

11. Cut total costs by sharing lab services and resources with other hospitals. Economies of scale result from this approach.

12. Increase test volume from sources outside the hospital to compensate for cuts in inpatient volume, and adopt competitive outpatient pricing. Fixed laboratory costs remain the same. The added business will entail only variable-cost increases.