Wednesday, 3 October 2012

Psychological assessments shown to be as valid as medical tests

My office spring-cleaning has revealed more useful resources: this time, a brief article from the APA Monitor on Psychology titled: Psychological assessments shown to be as valid as medical tests.

The article cites the 2001 report of the APA's Psychological Assessment Work Group, viewable as a pdf at

Although the article is now a decade old, it is still relevant today. Here's the first part of the abstract:

This article summarizes evidence and issues associated with psychological assessment. Data from more than 125 meta-analyses on test validity and 800 samples examining multimethod assessment suggest 4 general conclusions: (a) Psychological test validity is strong and compelling, (b) psychological test validity, is comparable to medical test validity, (c) distinct assessment methods provide unique sources of information, and (d) clinicians who rely exclusively on interviews are prone to incomplete understandings. 

Of course the strength of psychological assessments is nothing new to neuropsychologists, and this AACN position paper cites evidence about the utility of  neuropsychological assessments in diagnosing dementia (pp.10-11). However, it seems we need to get that information out to the broader public, including health advisors and policy-makers. For example, at the recent National Dementia Research Forum that I attended in Canberra, there was lots of information about biomarkers and diagnosis of dementia, but I didn't hear any speakers mention the empirically-demonstrated value of repeat neuropsychological assessments in the early diagnosis of dementia. In the Australian Institute of Health and Welfare report on Dementia in Australia, a search of the pdf available here found no mention of neuropsychology, except in the appendices or references.

We still don't have Medicare rebates for neuropsychological assessments in this country - which is a major barrier to early diagnosis of brain disorders across the lifespan.  I'm still hopeful that someone in the Medicare Benefits Office will take up our proposal (viewable here), and work out that a saving of $30,000 per patient with an early, neuropsychological-assisted diagnosis of dementia means that it is worth creating neuropsychology assessment, feedback and intervention Medicare items for all Australians with suspected brain dysfunction. This wouldn't be cost-shifting from State to Federal health systems, it would be creating better access to specialist psychological services for the thousands of people with brain conditions who cannot access them now.

The state health systems do not employ enough neuropsychologists to meet the demand for neuropsychological services. Our neuropsychology workforce is underutilized, with the majority of our neuropsychologists working in part-time jobs in the public sector,  because there aren't enough full-time positions. New graduates take on positions as research assistants or think of leaving the country because they feel pessimistic about ever getting full-time jobs. Ironically, it is hard to fill positions in South Australia or regional NSW or Victoria,  but even if new graduates took up those positions, there's probably not enough positions for the graduates, and there's definitely not enough neuropsychologists to provide the early diagnostic services needed by the estimated 1400 new cases of dementia each week in this country. Not to mention all the ABIs or other neurological conditions where cognition, behaviour, and emotion are affected.

If our clients could access Medicare, then every neuropsychologist who works in part-time public practice would be able to see one or two more patients per week: patients who aren't eligible for hospital-based services, and who can't afford to pay even the measley sum of $600 for a comprehensive assessment that takes the neuropsychologist 8 to 10 hours... Patients from rural, regional, and remote areas would be able to travel to see a neuropsychologist for an assessment if there's no service at their local hospital. Services would be available for urban dwellers who do not meet the intake criteria for hospital neuropsychology services (which often have prohibitively long outpatient waiting lists, if they have an outpatient service at all).

People with brain disorders miss out on access to the specialist psychological assessments they need to help with diagnosis and interventions, but people with mental health disorders can see psychologists for 10 or more hourly intervention sessions. Where is the equity in that???

The AACN position paper I mentioned above has a workable list of inclusion and exclusion criteria for neuropsychological services - neuropsychologists need to carefully screen referrals to ensure that we only see the patients where we can make an unique contribution, where no other professional can answer the referral questions. If we don't, we risk being swamped by inappropriate referrals, and we can focus on the patients who really need us to help shed the light of understanding and knowledge on their hitherto incomprehensible problems. We also need to debate amongst ourselves if neuropsychological assessment is necessary for every case of brain dysfunction - if someone has a confirmed diagnosis of MS or epilepsy, for example, we need to be able to argue why they need a neuropsychological assessment where education about the condition may suffice. Again, the AACN position paper sets out some good decision-rules for   rejecting referrals, for example, when

  • The patient has been diagnosed previously with brain dysfunction, and there is no expectation that the testing would impact the patient's medical management (p.5) 
Or for accepting referrals in cases of
  1. Deterioration in mental status or previous level of functioning, or 
  2. Onset of new abnormal neurological or psychiatric symptoms, or 
  3. Failure to adapt as expected to changing environmental conditions, or reasonable expectation that new symptoms or symptom exacerbation will occur as a result of changing environmental conditions. 
  4. In younger persons (children, adolescents, and young adults), an abnormally prolonged plateau in the course of normal development, suspected to be caused by central nervous system impairment. (p.6)
Our specialist skills are appreciated by neurologists, neurosurgeons, psychiatrists, geriatricians, paediatricians, and other medical specialists, it doesn't look like anyone is singing our praises loudly enough when it comes to government reports and health policy. Who would like to help?


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