Those who know public health know Prof. Irving Zola‘s “upstream vs downstream” parable. Irving Zola is a medical sociologist. His friend, John McKinlay, describes Zola’s parable in his 2019 article titled “A case for re-focusing upstream: The political economy of illness”1.
The “Upstream boat” sails through this upstream path.
Following is the reproduction of the parable;
” I am standing by the shore of a swiftly flowing river, and I hear the cry of a drowning man. So I jump into the river, put my arms around him, pull him to shore, and apply artificial respiration. When he begins to breathe, there is another cry for help. So I jump into the river, reach him, pull him to shore, apply artificial respiration, and then just as he begins to breathe, another cry for help. So back into the river again; another cry!
Again and again, without end, goes the sequence.
You know I am so busy jumping in, pulling them to shore, doing the same, that I have no time to see who the hell is upstream pushing them all in”.
This public health metaphor classic forces us to re-focusing our attention on the highest impact interventions. It becomes an effective tool within the Social Determinants of Health framework.
Graphical presentations of Zola’s parable
Progressive organizations employ this parable to make their mission clearer to everyone. Following are two examples of such graphics;
Sudbury and Districts public health in Ontario, Canada
The following graphic appears on the website, which belongs to the public health Sudbury and Districts in the Ontario province. It vividly explains Zola’s parable.
National Collaborating Center for Determinants of Health (NCCDH)
The above NCCDH infographic travels a little further; It divides the stream into three;
- Downstream
- Midstream
- Upstream
Stream-specific interventions
Downstream interventions
Let us begin with downstream determinants and their interventions. According to Zola’s parable, he saves lives one by one. So, the focus is on the individual – one unit. We can add one family also here.
We create strong scaffolds to save individuals from drowning. It also requires a lot of resources to search and bring those in danger to the shore.
We strive here to change the effects of the causes: by treating an illness, screening for it etc. Most of the healthcare budget spends on such activities: To improve service delivery and equitable access to services. However, these efforts do not remove the causes that fall them into the water.
Some examples:
The below is from Pamela M. Lantz’s 2019 article in the Milbank Quarterly.
| Downstream interventions | Midstream and upstream interventions |
| Supportive housing to chronically homeless people | Efforts to increase affordable housing in neighbourhoods, cities, and national levels. |
| Patient-centred interventions to improve health literacy | Broad education system reforms to improve health literacy |
Midstream interventions
The midstream approaches focus on improving working and living conditions and promoting healthy behaviours. According to the NCCDH, these changes occur at local, community and organizational levels. Unlike in the downstream interventions, here we attempt to change the causes of illnesses.
Upstream interventions
In contrast to the above two, the upstream interventions create positive environments that impact midstream and downstream conditions and interventions. Without upstream approaches, other interventions become unsustainable. These types of interventions either change or reform macro-level national and global policies.
In other words, the upstream interventions address “causes of the causes” and are also called “social determinants of health”.
With the help of Irving Zola’s river story parable, we can visualize the causes, causes of the causes, and the appropriate best return of investments.
References
- John B McKinlay (2019): A Case of Re-focusing Upstream: The Political Economy of Illness; IAPHS Occasional Classics, November 19 2019; https://iaphs.org/wp-content/uploads/2019/11/IAPHS-McKinlay-Article.pdf