In New Zealand as with many western societies there has and continues to be a growth in the use of laboratory testing. Growth is being driven by a number of factors including:
- An aging population. Older people tend to use more health resources.
- A focus on the management of chronic diseases such as diabetes.
- Increasing investment in primary care services.
- A move to more defensive medicine practice by doctors.
New Zealand is seeing a rise in the prevalence of obesity (http://www.moh.govt.nz/obesity). This will lead to an increase in the incidence of chronic disease and an increase in health service usage. Thus, it is not unreasonable to forecast a continued growth greater than population growth in the use of laboratory tests.
Growth in the number of tests has historically been at a greater rate than available additional funding. Consequently, a larger share of funding has gone in to laboratory services to the detriment of other services such as elective surgery.
Recent changes in the contracts for laboratory services have helped limit the cost growth. However, unless underlying volume growth is managed the contracting arrangements only provide short term relief.
There is large variety in referral for laboratory tests between doctors (Smellie, Stuart etal). The Ministry of health report 'Referred services management: building towards equity, quality, and better health outcomes' states that for New Zealand vaiety in referral exists and impacts on disadvantaged populations disproportionately. This demonstrates that not all parts of the population have equal access to laboratory services. Some people may be getting fewer tests than desirable while others may be being tested more frequently than required. Lord Carter in his report for the NHS also notes this point.
Many laboratory tests are potentially inappropriate (Lewandrowski K). Lewandrowski notes that up to 50% of laboratory referrals in the hospital environment may be unwarranted. This is based on the situation where the results of the laboratory test do not impact on the treatment plan for the patient. If this range of testing is inappropriate in the hospital environment is inappropriate it can be assumed that there will be a level of inappropriate testing in the primary care setting.
All these factors lead to the conclusion that a focused programme on practitioner training and feedback on individual practice will potentially lead to a number of positive outcomes:
- Reduction in disparities of testing levels between practitioners and the patients they serve.
- Improved health outcomes.
- Improved quality of requests.
- Appropriate growth rates in utilisation leading to improved management of cost to the DHBs.
- There are a number of examples of programmes that have focused on referral quality management.
Some important lessons have been made that would inform a local programme:
- Feedback to doctors can improve utilisation (Winkens etal, Bohen etal, Wim etal).
- The number of tests requested is in reverse proportion to the years experience of the doctor and the number of hours they work (Bugter-Maessen).
- Feedback needs to be consistent and maintained to ensure sustainable change (Barth, Bohen)
- Request form design can impact on the number of tests (Barth).
- Computer decision support tools may help (Bohen).
- Reduction in lab tests does not lead to greater hospital admissions (Winkens BMJ).
- Reduction in utilisation may decrease the number of false positives and eliminates unnecessary follow-up procedures (Lewandrowski)
- There can be an economic return (Winkens)
- There is variability in assessment of lab test utilisation between pathologists leading to quality questions on feedback (Bidels etal)