Out of stock syndrome: an under-recognised public health problem

Written for ISIUM by Rob Moulds

Two case studies

Case 1

A routine Sunday morning ward round at a central referral hospital. A young man had been admitted on Friday afternoon with presumed septicaemia. His blood culture results on Saturday morning had been reported as growing gram-positive cocci in clusters – probably Staph aureus. The IV cloxacillin therapy commenced on admission had been continued.

He was stable, but his drug chart revealed the bad news. He had unexpectedly fallen victim to the dreaded out of stock (OOS) syndrome – instead of the initials of the person administering them, the last two doses of cloxacillin had OOS recorded beside them. The prescription was changed to ceftriaxone.

Ceftriaxone was in stock and available on a Sunday. He recovered.

Case 2

A specialist medical outpatient clinic at a divisional hospital. A middle-aged woman on long-term treatment for type 2 diabetes and hypertension attended for routine 3-monthly review. She reported no symptoms. Her blood pressure on the last visit was 135/85. This visit it was 160/110.

She reported that she was unable to fill her last two monthly repeat prescriptions for enalapril because the pharmacy said they were out of stock. The OOS syndrome was diagnosed. A phone call to the pharmacy established new stock of enalapril had arrived within the last week. The patient was advised to recommence the enalapril.

Overview of the OOS syndrome

There is no agreement on a precise definition of the OOS syndrome, but a working definition could be ‘the unintended unavailability of an essential drug at the point of care’.

It is anecdotally common, but poorly documented and researched by the public health community. In particular its natural history, prognosis and long-term outcomes are largely unknown. However, at the least it leads to healthcare worker frustration, and at worst leads to probable avoidable deaths. Three subtypes have been suggested – acute, chronic relapsing, and chronic progressive. However, it is not known if these represent different syndromes or are subtypes of the same syndrome.

Aetiology

Being a syndrome, there are multiple factors that can lead to the same end result, and the relative contribution of the different factors can vary greatly from time to time and from place to place. They can also vary depending on whether the syndrome is acute, chronic relapsing, or chronic progressive.

Factors that can be variably involved include:

• Poor prescribing e.g. practitioners not following local guidelines and/or over prescribing a new drug
• Poor stock control e.g. controllers routinely rolling over previous orders and not noting or anticipating changing prescribing recommendations
• Poor communication between central and peripheral stock controllers e.g. only sending new supplies on fixed dates or after stocks have run down to very low levels
• Poor tendering processes e.g. insistence on multiple tenders, or alternatively use of a preferred tenderer, by financial controllers.
• Poor supply contracts e.g. no enforceable penalties if a supplier does not adhere to a contract
• Poor oversight e.g. corrupt siphoning of essential drugs to private pharmacies going undetected.

Clinical features and diagnosis

The clinical features and diagnosis depend on whether or not the syndrome is hospital-acquired or community-acquired

Hospital-acquired (inpatients)

The diagnosis of the presence of the syndrome is straightforward – the letters OOS appear in the drug chart where the signature of the person administering the drug should appear. The patient might or might not have clinical features related to the omission. Unfortunately, there are seldom any memos or other warnings of the outbreak of the syndrome.

Hospital-acquired (outpatients) and community-acquired

The diagnosis is usually only made when the patient returns for their next visit and reports they could not fill either the initial prescription or one of its repeats. The patient might or might not have clinical features related to the omission. Future compliance is often compromised, especially if the treatment was for an asymptomatic condition, e.g. elevated blood pressure or type 2 diabetes. As with the hospital inpatient form of the syndrome, there are seldom memos or other warnings of a local outbreak of the syndrome

Investigations

Investigations to establish the presence of the syndrome are seldom required as its presence is usually obvious.

If investigations are undertaken, e.g. a phone call to the pharmacy, they usually only have moderate sensitivity or specificity in ruling in or ruling out the presence of the syndrome.

Investigations to establish the cause of the outbreak of the syndrome are seldom useful because all have low sensitivity and/or specificity.

Management

Being multifactorial in origin, management of the syndrome is difficult and usually involves multiple and ongoing interventions. The syndrome has also proven to be remarkably resilient and resistant to treatment and is prone to outbreaks despite the ongoing implementation of previously successful interventions.

Management of an acute outbreak requires alternative strategies of patient management to be devised, often at short notice. These alternative strategies then need to remain in place until the acute outbreak subsides and the relevant stock returns.

Management of chronic outbreaks can be more difficult, although the same principles of utilising alternative strategies for patient management still apply.

Long-term prevention

No long-term preventive strategies have been proven to be entirely successful, including the promotion of prescribing guidelines, and implementation of a wide range of different stock control procedures.

However, reduction in the frequency and severity of outbreaks can likely be achieved by encouraging the following:

• Prescribers to adhere wherever possible to agreed prescribing guidelines. This enables better prediction of likely usage, and thus more accurate stock control, of the essential drugs recommended for use in the guidelines
• Stock controllers to consider changes to guidelines in addition to historical usage patterns when placing stock orders
• Better liaison between stock controllers and prescribers so that prescribers are given as much warning as possible of likely shortages so they can plan appropriate alternative therapeutic strategies, and stock controllers are given as much warning as possible of likely changes to prescribing patterns so they can modify stock orders appropriately
• Ensuring tenders and supply contracts pay as close attention as possible to likely future changes in usage, and also ‘fall back’ provisions should unforeseen problems with supply arise during the term of the contracts
• Certainty of supply is given weight at least equal to price and quality when essential drug purchases are being negotiated.

A strategy unlikely to be successful is the appointment of a ‘fix-it person’ whose main key performance indicator (KPI) is to have the problem solved within a stipulated period of time.