Doctors and Aging – are we throwing the Wisdom out with the Bathwater?

Aging Doctors have been in the news lately – are they safe and competent? Are they keeping up with current practice? Decline in performance is inevitable with age. In particular, dementia increases with age and the line between “forgetful” and significant cognitive decline can be difficult to define. Cerebral decline causing physical symptoms such as Parkinson’s Disease also increases with age.

Licensing agencies such as AHPRA in Australia are proposing regular reviews of performance based on age to capture decline before it become problematic. But will these reviews detect such decline and improve safety or simply impose cost and inconvenience ?

“Fluid” and “Crystalline” Intelligence

The concepts of “fluid” and “crystalline” intelligence were first proposed by Cattell in 1963.

Fluid intelligence can be thought of as problem solving ability by reasoning – “thinking on your feet”. Crystalline intelligence involves problem solving using a “library” of past memories – ie an heuristic pattern recognition process. This can be seen as “experience” and perhaps even “wisdom”. Fluid intelligence declines with age, particularly if it is not exercised and trained, but crystalline intelligence continues to increase with age. – see below

Fluid Intelligence vs. Crystallized Intelligence

The Age of Peak Performance

A decline in performance is inevitable with age, particularly for those who achieve elite status.

For careers requiring peak physical performance such as gymnastics, competitive sport or elite athletics, performance peaks early – often in the 20s or 30s.

In careers that rely on fluid intelligence performance peaks typically in the 40s or 50s. In a study of Nobel Laureates, the most common age for producing a Magnum Opus was in their 30s. Poets typically peak in their 40s, while novelists take a little longer. High achieving scientists spend their later career promoting their achievements and teaching. In the business world many older job seekers complain that they are not hired. Is this because of “ageism”, or is it because business requires “fluid intelligence”?

What type of intelligence makes a good doctor?

It is noteworthy that many doctors continue to practice into old age – some even into their 80s and 90s. These older doctors appear to be functioning effectively. This would suggest that their practice depends more on crystalline than fluid intelligence – ie their “experience” is valuable. In clinical roles such as Primary Care they work from their library of patterns built up over a lifetime of practice. They have a long term relationship and knowledge of their clients.

What makes a good Surgeon?

Some Procedural Medical Roles such as Surgery depend on manual performance and as well as a functioning cognition. The performance of surgery requires skill in the manual techniques involved, such as dissection and suturing. It also needs skill in planning, sequencing and detailed knowledge of anatomy and pathology. In the surgical world of today many techniques are now endoscopic rather than “open”. Here, the ability to visualize and manipulate in 3 dimensions is important – this is arguably a “fluid intelligence” skill. Impairment of vision or physical ability such as with Parkinson’s disease could be expected to impair surgical performance.

But as well as the manual skills needed for surgery, clinical skills are still necessary for the “complete surgeon ” – as the old adage says – “choose well, cut well”. While the surgeon does not have to deal with undifferentiated or complex/multimorbid presentations as in Primary Care, he/she must still have good clinical method and the ability to judge whether intervention will improve the outcome. Here experience and “crystalline intelligence” is important.

Screening for impairment.

We know that it is difficult to show benefit from screening in general. A general checkup does not improve outcomes (see my article https://tjilpidoc.com/2023/05/29/get-your-checkup/). It seems that while many screening tests have been proposed, very few pass the the tests of early detection, possible intervention and improved outcomes. But here the test is simply to detect impairment and intervene before harm is done – is there a fair and reasonably economical way to screen doctors for impairment?

The Health practitioner regulation national law defines an impairment of a health practitioner as “… a physical or mental impairment, disability, condition or disorder (including substance abuse or dependence) that detrimentally affects or is likely to detrimentally affect … the person’s capacity to practise the profession”.

Currently AHPRA relies on reporting of impairments by the practitioner themselves, other practitioners, clients or the General Public. Reports can be anonymous though this does make progressing them difficult. There are various tools and scales available to measure impairment but these are generally in the context of compensation or disability assessment for benefits.

But now AHPRA is proposing to screen doctors who are apparently functioning normally on the basis of age.

Perhaps the closest analogy to the proposed AHPRA assessment is the “Fitness to Drive” process that GPs must perform on older drivers. While it is relatively easy to perform visual acuity assessment, cognitive ability is much harder to assess. Crude tools such a Mini Mental State Examination (MMSE) will show gross deterioration but more subtle deterioration is difficult to detect. One meta-analysis looked at 2247 articles. (4) Only 4 met psychometric criteria and only one met “clinical utility criteria”. The study authors concluded that on road functional testing remained the gold standard of assessment. I am not aware of similar studies aimed at Medical practitioners. Perhaps the gold standard here would be functional testing by another practitioner? This is difficult enough with trainee Registrars. The cost and difficulty of such a process are obvious. In practice most impaired drivers are detected as a result of accidents or by their relatives driving with them – the mandatory driver tests become an opportunity to stop them driving

I could find no studies which showed actual measured improvements in safety with driver testing though there are many statements on various websites of its necessity. In our practice, it appears that consensus drives what we do. As with much in the world today “say it often enough and it becomes truth”!

Conclusion

AHPRA is proposing a regular mandatory checkup for doctors over 70 to assess their competence. Clinical skills are based largely on “crystalline intelligence” which increases with age. Screening for disease or impairment is difficult and there is no evidence backed, reasonably economical method to assess subtle cognitive impairment. We may be throwing away experienced doctors who provide a valuable service in the Heath system without improving clinical safety.

References

(1) “Your Professional Decline Is Coming (Much) Sooner Than You Think”

The Atlantic

https://www.theatlantic.com/magazine/archive/2019/07/work-peak-professional-decline/590650/

(2) Raymond B Catell
THEORY OF FLUID AND CRYSTALLIZED
INTELLIGENCE:
A CRITICAL EXPERIMENT

Journal of Educational Psychology 1963 54(1) 1-22