# How to estimate the number of surgeries per year for countries without relevant data

For many countries, including the full range from underdeveloped to highly developed countries, no data about the number of surgeries per year is available.

However, the 2008 Lancet publication Weiser et al. An estimation of the global volume of surgery: a modelling strategy based on available data, DOI 10.1016/s0140-6736(08)60878-8

provides a simple method of roughly estimating this number.

According to table 2, countries can be assigned one of several expenditure stata regarding their health care spending, each with an assigned Mean estimated surgical rate per 100 000 population :

• Poor-expenditure countries: 295
• Low-expenditure countries: 2255
• Middle-expenditure countries: 4248
• High-expenditure countries: 11110

#### How to classify countries:

According to the above-cited paper, the countries shall be classified by the per-capita total yearly expediture on health:

• Poor-expenditure countries: Less than 100$ • Low-expenditure countries: Between 101$ and 401$ • Middle-expenditure countries: Between 401$ and 1000$ • High-expenditure countries: More than 1000$

There are many source from where you can acquire this data. One of the easiest-to-use sources is the WHO country profile page. For example, you can see that Angola had a per-capity health spending of 51\$ in 2020. This clearly puts Angola into the Poor-expenditure countries considering our criteria above.

#### Calculation example:

Consider a middle-expediture country with a population of 22.8 million inhabitants.

According to the formula above, a rough estimate for the number of surgical proceducers in said country can be calculated by:

[latex display=“true”]\text{Number of surgeries} \approx \frac{\text{Population number}}{100000} \cdot \text{Middle expenditure mean surgical rate}[/latex]

Regarding our example:

[latex display=“true”]\text{Number of surgeries} \approx \frac{22.8*10^6}{100000} \cdot 4248 = 968544[/latex]

Hence, we can roughly estimate that 968544 surgical procedures are performed in said country per year.