Research of ALz Test.

Objective

To determine whether ALz Test scores and screening results are associated with Mini-Cog screening results, and to evaluate the level of agreement between the two tools.

Research hypothesis

The analysis tested whether ALz Test results were associated with Mini-Cog screening results. The research found that people with concerning Mini-Cog results were significantly more likely to receive a concerning ALz Test result.

This does not mean that the two screening tools are equivalent or interchangeable.

Design

Paired, cross-sectional comparison of two cognitive screening instruments. The historical website described the research as a case-control study, but the available records do not provide enough information to confirm that design.

Setting

Testing was reportedly conducted face to face in participants' homes. Participants completed the Mini-Cog, which includes three-word recall and a clock-drawing task, and the ALz Test, which consists of 15 multiple-choice picture questions.

Participants

The analysis included 59 participants with evaluable results from both the ALz Test and Mini-Cog. Three additional ledger entries were repeat visits and were not counted as separate participants. One participant was excluded because paralysis prevented completion of the Mini-Cog clock-drawing component.

Measurements

The ALz Test score was calculated as the number of incorrect answers among 15 questions. A result of five or more incorrect answers was classified as concerning. A result of four or fewer incorrect answers was classified as not concerning.

Mini-Cog scores of 0-2 were classified as concerning, while scores of 3-5 were classified as not concerning. Four historical response cells were obscured, so the analysis used two scoring scenarios: one treating those responses as correct and another treating them as incorrect.

Because Mini-Cog is a screening instrument rather than a clinical diagnosis, the analysis measured association and percent agreement, not diagnostic sensitivity or specificity for Alzheimer disease.

Results

Participants with concerning Mini-Cog results answered substantially more ALz Test questions incorrectly than participants without concerning Mini-Cog results.

• Median incorrect answers: 6 versus 3
• Mann-Whitney p-value: 0.00011-0.00019
• Positive percent agreement: 65.5%
• Negative percent agreement: 73.3%-76.7%
• Overall agreement: 69.5%-71.2%
• Odds ratio: 5.23-6.24
• Fisher exact p-value: 0.0016-0.0040
• Cohen's kappa: 0.389-0.423
• Exploratory AUC: 0.782-0.791

The findings were similar under both methods of handling the obscured historical responses.

Limitations

This analysis was reconstructed from archived ledger photographs rather than original case-report forms. The available records do not establish the recruitment method, participant demographics, assessment order, assessor blinding, exact testing dates, or raw Mini-Cog totals.

Four ALz Test response cells were obscured. One participant could not complete the Mini-Cog clock-drawing component because of paralysis. This also shows an accessibility limitation of using a drawing-dependent screening tool as the comparator.

The study was small and did not use an independent clinical diagnostic reference standard. Therefore, it cannot establish whether ALz Test diagnoses Alzheimer disease or another cause of cognitive impairment.

Previously reported figures of 92% correct identification and 8% false-negative results could not be reproduced from the archived ledger and should not be presented as current findings.

Conclusion

The ALz Test showed a statistically significant relationship with Mini-Cog screening results. People with concerning Mini-Cog results were significantly more likely to receive a concerning ALz Test result. The two tools agreed in approximately 70% of participants.

These results provide preliminary support for further evaluation of the ALz Test as a brief first-step cognitive self-check. They do not establish that the ALz Test is as effective as Mini-Cog, that the two tests are interchangeable, or that the ALz Test can diagnose or rule out cognitive impairment.

A larger, independent prospective study using an appropriate clinical reference standard is needed.

About Mini-Cog

Mini-Cog is a brief cognitive screening instrument combining three-word recall with a clock-drawing task. A total score of 0-2 indicates a higher likelihood of clinically important cognitive impairment. A score of 3-5 indicates a lower likelihood of dementia but does not rule out some degree of cognitive impairment.

Mini-Cog is used to identify people who may benefit from further clinical evaluation, but it is not itself a diagnosis.

Permission to use Mini-Cog in the historical research concerned the comparator instrument only. It did not constitute endorsement, validation, approval, collaboration, or supervision of the ALz Test.