Table 1.
Consolidated principles for population-based screening
| Principle | HICs | LMICs |
|---|---|---|
| Disease/condition | ||
| 1. Epidemiology of the disease must be understood, and it must be an important health problem | ++++ | ++++ |
| The burden of CKD is unquestionably high and increasing worldwide. Much is known about the epidemiology of CKD and about risk factors for progressive kidney function loss. | The burden of CKD is high in LMICs, and the potential risks associated with kidney failure are potentially higher because RRT may not be available. | |
| 2. Natural history should be understood, and a preclinical phase must be detectable | ++++ | +++ |
| Although there may be special populations for which less is known about the natural history, this criterion is generally met. | ||
| 3. Target population for screening must be defined | +++ | +++ |
| There are some uncertainties about the precise criteria that should be used. For example, should the target population be defined by age >18 yr or >40 yr? Should there be an upper limit or exclusions of certain groups? | ||
| Test/intervention principles | ||
| 4. Screening test performance characteristics: test(s) should be accurate, safe, acceptable, and affordable | ++++ | ++++ |
| Test performance and costs are generally favorable. | There may be opportunities to reduce cost by using dipstick urinalysis rather than ACRs to detect cases, but this might increase false positive rates. | |
| 5. Interpretation of screening test results: tests should have clear thresholds | ++ ++ | |
| There are some uncertainties about which criteria should define a positive screening test. For example, should eGFR 45–59.9 ml/min per 1.73 m2 but without albuminuria be considered a positive or a negative test? Still, this criterion is generally met. | ||
| 6. Postscreening test options: there should be an agreed-upon course of action for follow-up, treatment, and improved outcomes | ++ | + |
| For people with diabetes, hypertension, and perhaps vascular disease, post-test management for newly identified cases of CKD will differ little from those without CKD. | Same as for HICs. Also, some treatments that might be prescribed to CKD cases in HICs (e.g., sodium-glucose cotransporter 2 inhibitors for people with concomitant diabetes) are unaffordable in LMICs. | |
| Program/system principles | ||
| 7. Screening program infrastructure: there should be adequate existing resources or a plan to develop sufficient resources for all | +++ | + |
| Population-based screening would require substantial new resources. Depending on the target population, there may be opportunities to integrate CKD screening with screening for other noncommunicable diseases. | Infrastructure needed for testing alone is not available in most LMICs. Also, management of detected cases over years or decades would be difficult or impossible in most LMICs. | |
| 8. Screening program coordination and integration: screening should be coordinated and integrated into broader health system | +++ | + |
| This would be generally possible in HICs. Avoiding overtesting is a potential concern, as well as overinvestigation (unnecessary follow-up of positive screening tests). | Few LMICs would be able to integrate CKD cases identified by screening into the broader health system. Many LMICs struggle to manage known CKD cases. | |
| 9. Screening program acceptability and ethics: all components should be ethically acceptable to participants and professionals, and methods to ensure informed choice should be in place | ++++ | ++ |
| No concerns. | Labeling people as having CKD without providing effective management causes harm. | |
| 10. Screening program benefits and harms: benefits such as increased function and quality of life or decreased mortality should be greater than harms (such as from overdiagnosis and overtreatment) | ++ | + |
| In the absence of high-quality evidence demonstrating benefit, it is unknown whether this criterion is met. Given the comments for criteria 6 and 9, there is more uncertainty about a favorable benefits/harms ratio in LMICs than in HICs. | ||
| 11. Economic evaluation of screening program: economic evaluation should assess full costs of operating screening program, compared with opportunity costs of allocating resources to alternatives | + | + |
| Even making very favorable assumptions about the benefits/harms ratio, population-based screening is not cost effective in HICs and may be more problematic LMICs. | ||
| 12. Screening program quality and performance management: screening program should have clear goals, objectives, and monitoring for quality control and performance targets | +++ | + |
| Electronic medical records and associated algorithms to guide management could enhance the quality of care for detected cases, while simplifying quality control. However, such integrated systems are not yet widely available. | Most LMICs do not have the capacity to ensure or measure the quality of care in existing CKD cases; existing capacity is likely to be adversely affected by an influx of new cases. | |
+, extent to which each principle is met in high-income and low-middle-income countries.