When I use a word . . . Drug stock-outs

Drug shortages

Two years ago colleagues and I published two papers detailing various aspects of drug shortages.12 We covered definitions of the relevant terms, causes of shortages, the harms they can cause, and potential solutions.

To do this, we looked for published definitions, of which we found 79. We also searched PubMed, Medline, and EMBASE to the end of 2022, initially using the term “shortage*.” However, this resulted in many thousands of hits, and we therefore restricted our search to the use of the term in titles of papers, of which we found about 6700. My most recent search has extended this to nearly 8000.

Defining drug shortages

In principle “shortage” is not hard to define. The Oxford English Dictionary (OED) does it succinctly: “Deficiency in quantity; the amount by which a sum of money, a supply of goods, or the like, is deficient.”3

However, when it comes to defining a drug shortage, problems arise.

First there is the question of extent, and specifically the difference between a local deficiency and a general one. For example, a deficiency can affect only a single pharmacy, hospital, or other outlet. On the other hand, it may be more widespread and affect several such outlets, for example in a town or a city, in a country or a continent, or worldwide.

Of the 79 definitions we surveyed, 14 were actually definitions of a local deficiency, commonly called a stock-out. This term, which need not imply a general shortage, denotes the complete absence of a medicine from the shelves of any outlet that would be expected to stock it, typically a pharmacy. A stock-out has been variously defined as an inability of a pharmacy to deliver a drug to a patient, zero usable stock, complete absence of a medicine in stock, no “medicine facility shelf,” and absence of a medicine at a health facility level.1

Then there are difficulties in specifying various aspects of a widespread shortage, among which we identified the following:

● multifarious causes of disruptions of the supply chain;

● specifying the different types of outlets from which medicines are generally obtained;

● specifying the duration of a deficiency that would qualify it as a shortage, depending for example, on the harm that it might cause;

● differences in the so-called forgiveness of different medicines, contrasting, for example, unforgiving oral contraceptives, which need to be taken daily, and highly forgiving statins, several doses of which can be missed without incurring loss of long term efficacy;

● variability in the importance of a deficiency to different patients.

We therefore decided to devise an operational definition of a shortage:

(a) by enumerating the main processes whereby a medicine is manufactured and delivered to the patient: obtaining the raw materials, synthesis or extraction of the active ingredients, formulation of the authorised product, and delivery to a pharmacy;

(b) by listing the main causes of shortages that have been described and related factors; and

(c) by specifying the two main outcomes of failure in the system: stock-outs and shortages.

Even then, we were unable to specify precisely the level of deficiency that turns a local stock-out into a national shortage.

Scoping the literature

Although in our original systematic review of the world literature we searched for papers dealing with stock-outs, those were outnumbered about 100 to one by papers dealing with shortages. We therefore based our primary operational definition of a drug shortage on the literature in which deficiencies were described as shortages rather than stock-outs. Here, therefore, I concentrate specifically on stock-outs.

As a start I searched PubMed up to the end of 2024 for papers whose titles featured the terms “stock-out*” or “stockout*.” After elimination of duplicates there were 73 hits in all, about 70% of which have appeared in the past 10 years.

It was not always clear in the papers that I found that the term “stock-out” was not being used as a synonym for “shortage.” In one case for example, the authors used the term “national stock-out.” Presumably, in such cases there was no evidence of a shortage in other countries. However, this illustrates a problem with the definition of a shortage, since the term is often used to describe a deficiency in a single country.

For the present I have analysed the papers I found with “stockout*” or “stock-out*” in the titles as a batch, separate from papers whose titles included the term “shortage*.”

What was most striking about the collection of publications was the preponderance of authors from Africa, representing 16 countries in all: Botswana, Cameroon, Congo, Ethiopia, Ghana, the Ivory Coast, Kenya, Mozambique, Namibia, Nigeria, Rwanda, Senegal, South Africa, Tanzania, Uganda, and Zambia. These comprised almost 75% of all the countries represented. In Asia, only India, Pakistan, and Timor-Leste were represented (one or two each), and in Europe France, Spain, and the UK (also one or two each). There were also a few papers from the USA and one from Brazil. A handful came from organisations: the Pan American Health Organzsation, UNICEF, and the World Health Organization (one or two each). However, I doubt that the distribution of countries represented in this sample reflects the true distribution of countries in which stock-outs actually occur.

Given the preponderance of African and Asian countries involved in this sample, it was not surprising that just over half of the papers dealt specifically with antimicrobial agents, including antibiotics in general, antimalarial drugs, antiretroviral drugs, antituberculosis drugs, and vaccines. In addition, nine covered contraceptives, and most of those also came from authors in African countries.

Causes

The causes of shortages can also cause stock-outs. These include problems in obtaining raw materials, difficulties in extraction of active principles from raw materials or in chemical syntheses, problems with formulation of active ingredients, difficulties in obtaining marketing authorisation, and distribution problems.

Clearly all of those causes can also contribute to stock-outs. However, stock-outs are more likely to be owing to poor management at a local level. Problems include local funding difficulties, difficulty in procurement and transport, insufficient or poorly trained staff, and poor data management, including inaccurate tracking of use of products, insufficient control of replenishment, and poor inventory management.45 Parallel trade, in which goods are bought cheaply in one place to be sold at a profit elsewhere, has also occasionally been blamed.6