Are we outdating reagents too soon? Here are ways to extend the shelf life of many lab products without jeopardizing test results.

You have just run out of coagulase plasma and are reaching for the last unopened box when the markings hit you right between the eyes: outdated! Now what? Do you throw the box out? Borrow from another lab? Send the tests out? Ask hematology for pooled plasma? Or could the reagent still work beyond the posted outdate?

This kind of situation will increasingly plague laboratorians operating on tight DRG margins. Closer inventory control is the order of the day, and it can lead to supply shortages. But it would also seem to lower the risk of outdating. If smaller reagent quantities are kept on hand, they will probably be consumed before their time is up.

Here's why that logic fails and outdating all too often does occur:

* Manufacturers frequently assign "industry standard" outdates, kept short so that inventory of their products doesn't pile up.

* Food an Drug Administration approval for outdate extension takes months or even years following the submission of reams of quality control data. Some companies simply choose not to spend the time to compile the data.

* Supply houses ship short-dated items to turn over their own inventory. It's not unusual for a laboratory to order a six-month supply of reagents only to find out that the shipment that's delivered carries a three-month outdate.

* No matter how little they need, smaller laboratories often must buy supplies packaged in case lots. They don't have the option to split cases and trim their orders. Needless to say, a large amount of reagent can outdate before an entire case is used.

* Nobody possesses a crystal ball with a precise picture of future test volume. Some months it's a feast; others, a famine. Meanwhile, the clock ticks, and the outdate approaches.

Adding to our frustration are those ever-present inspectors whose eyes take on a hawk's glint at the sight of an outdated reagent. As a result, we don't hesitate to toss reagents into the dumpster just before an inspection.

Who pays for all of this? Among others, any patient or third-party payer who is outside the prospective payment system. Who else pays? We do, and our bottom line suffers for it. Often, the waste is unnecessary. What scientific data exist to mandate that a frozen MIC tray that outdates on July 31 is useless on August 1? What magic between 11:59 p.m. and 12 a.m. renders such a supply untouchable?

This article will detail tactics our independent laboratory has used to salvage reagents. We provide on-site testing and reference services for three hospitals and also operate 16 outpatient labs. I serve as the firm's microbiology coordinator and as technical director of a 107-bed hospital laboratory. The cost-saving suggestions that follow are based on our quality control experiences, research, and contact with supply houses and manufacturers.

First of all, teaching laboratories can defray student supply expenses by performing careful wuality control to determine which outdates can be used as teaching materials. If properly stored, an outdated box of bacterial identification strips will provide a wealth of information for students. The expense of educational materials makes it necessary to economize either in this manner or, less preferably, through reduced hands-on activity. Even marginal materials can be used to teach instrument troubleshooting--an often neglected aspect of medical technology education.

Our independent lab facilities provide clinical training for MLT students from a local vocational school. Having them work on monitored outdates saves us at least $500 annually just for the microbiology rotation.

Outdated prepared culture media can also be used to maintain stock culture organisms. The very fact that a stock organism is able to grow on an outdated plate or slant or in broth verifies that the media still perform adequately. In addition, such media can be used to send cultures to referral laboratories or health departments. For example, our state health department prefers tubed media, which we don't normally use. It would be very expensive to keep purchasing a fresh supply just for this periodic testing.

If CAP guidelines for the visual inspection of culture media are observed--to make sure plates are smooth and adequately hydrated and tubed media are not dried or loose from the sides--outdating won't matter in these cases. The savings may be small, less than 5 per cent of total media, but the approach makes it possible to keep esoteric products available.

It is also important to talk to manufacturers. When introducing new systems, kits, or reagents, they usually set a short date because there is no track record for lasting performance. But innovative packaging and the manufacturer's quality control often extend a product's stability long past the initially assigned outdate.

Manufacturers keep records of quality control checks on each lot number throughout the product's shelf life and sometimes beyond that date. In many cases, these records become the data base for gaining an outdate extension. A phone call to check on the status of a product soon to be outdated can lead to pleasant surprises. You may find that the FDA has granted approval for extended dating since your shipment was produced, very possibly on data submitted for your lot number. In that event, ask for written verification of the outdate adjustment and continue using the product, assuming it stands up to your in-house quality control.

That's what we did when suddenly faced with a surplus of short-dated microbiology supplies. Since the outdate had already gone from six to nine and then to 12 months, we called the manufacturer to see whether there had been a further extension. Lo and behold, the firm had recently received approval for a longer outdate. The phone call saved us and our local supplier, who had been similarly overstocked, considerable expense.

We have all seen progressively longer outdates assigned to culture collection materials, kits for rapid and routine identification, and latex or co-agglutination reagents. Frozen MIC panels, for example, went from eight to 28 weeks over an 18-month period. Such an adjustment generally reflects the results of product stability testing by the manufacturer, not reagent formulation changes.

Communication with a sales representative or supply house can also prevent substantial outdate losses. Before placing an order, estimte how long it takes to use all of the product. Ask for an outdate that is 1-1/4 to 1-1/2 times as long as the projected usage period, and get it in writing on the purchase order. Then, it you don't receive exactly what you ordered, send it back.

We have far fewer ordering headaches now that we insist on a written guarantee. Being adamant is the key. Our laboratory once requested a six-month outdate for amylase determination kits; with a switch to micro volumes, it took much longer to use up each kit. The supplier initially overlooked this change and sent our usual order. After we refused to accept a shipment with less than one month left unitl the outdate, the supplier started taking our requests seriously.

Practice consumerism. Check out the quantities in which supplies are available, and ask if you can purchase shelf packs instead of case lots. It's much less costly to order smaller amounts of short-dated supplies more often than to have to discard a half-empty case as the outdate approaches.

If you must have a product, but it's sold exclusively in a volume you can't ever hope to use, chances are another local laboratory has the same problem. Phone over there. You might be able to split a case, with each laboratory alternating the order. That way, the labs don't have to bill each other for the shared supplies.

Our firm operates a central purchasing office that orders and allocates all outpatient lab supplies. Client hospitals place their own orders, but they receive discounts based on the firm's total volume. The hospitals split or share orders. The antimicrobial removal device is one example. Since physician requests for ARDs are infrequent, labs often can share one case.

A CAP inspector once told me: "I don't want to check your Salmonella antisera for the outdate. What I really want to see are your QC records. Antibodies don't outdate." This may sound a bit startling, but the statement rings true. Quality control really can be a measurement of a product's outdate. This way of thinking should become better established as prospective payment grows.

After all, we are trained professionals dealing in science--and science is experimental. No pure scientist would ever use anything to make a determination without first controlling it. Laboratories currently spend sizable amounts of money to quality control indated items, which at least in microbiology rarely fall out of control. Why then blindly take the outdate at face value? Being scientists, shouldn't we experimentally determine the validity of an arbitrary expiration date?

The cost of controlling one strip of a bacterial identification panel from an outdated package is less than 1/10 the amount lost if the box is discarded. Weekly QC of outdated kits and daily QC of such reagents as catalase, oxidase, and coagulase plasma are reasonable measures.

Do not misunderstand. I am not advocating that we take a step backward, nor am I promoting slipshod, under-the-table practices. But history has demonstrated that outdates are indeed arbitrary and vary based on storage and handling procedures. A Colleague once told me that during the 1960s a large amount of World War II vintage Salmonella typing sera was found buried in a warehouse. Some 20 years after production, the antisera performed just as well as a brand new batch.

Of course, quality control can't serve as the determining factor for stability on all supplies. Certain products of biological origin, such as coagulase plasma, are subject to rapid deterioration or may be less stable than items with inorganic components, such as a commercial bile solubility reagent. Even so, a product's track record and responsible quality control performed by professionals, coupled with industry efforts to increase product outdates, can spell substantial savings for any laboratory.

There's a paucity of data available outside industry regarding post-outdate shelf life. I believe that DRGs will force us to accumulate that data in order to see where our money is really spent and where it can be saved.

Let's face it, we are all under the gun to produce high-quality work and pinch pennies at the same time. Controlling our outdates may not solve the entire cost containment problem, but it is a good place to start.

Microbiologists are already questioning the need for routine quality control of indated items at the frequency specified by inspecting agencies. The microbiologists have the data, and some quality control changes have already been made.

What's next then? Applying the rpinciples outlined in this article, we can cut the volume of outdated materials by ordering less; use outdates for teaching; and communicate more effectively with dealers and manufacturers.

One more thing: Careful quality control and record keeping of all expendables can help give us a voice in easing the outdate dilemma. For example, we can submit--to manufacturers, inspecting agencies, and regulatory bodies--written summaries of data on performance past outdate for items that have extended stability. These summaries can be presented along with requests for outdate flexibility and investigations of the validity of currently prescribed shelf lives.

Guidelines can and should be established for extended use past the outdate for the more stable products. For example, indole and oxidase test reagents are extremely stable yet may carry unrealistically short outdates. These guidelines could include such easily measured parameters as proper storage conditions--temperature and exposure to light--and quality control. Guidelines for extended use under these conditions could be printed on the package insert, much as the supermarket does with temperature-dependent outdate extensions for dairy products.

This type of policy, already FDA-approved for food, is long overdue for the diagnostic products we use.