Analysis of reciprocal creatinine plots by two-phase linear regression

Area of Science:

• Nephrology
• Biostatistics
• Medical Informatics

Background:

• Serial plasma creatinine measurements are standard for monitoring renal disease progression.
• The rate of renal function change is often represented by the slope of reciprocal creatinine concentration over time.
• Identifying subtle but clinically significant changes in this slope can be challenging.

Observation:

• A novel application of two-phase linear regression using microcomputers is presented.
• This method fits two intersecting lines to estimate the point of slope change and its confidence intervals.
• It avoids pre-determining the time of change, mitigating bias associated with treatment alterations.

Findings:

• The two-phase regression accurately identifies and characterizes changes in the slope of renal function.
• It provides statistical and clinical significance evaluation of detected slope changes.
• Graphical output aids in the interpretation of renal function trends.

Implications:

• This method offers improved precision in detecting therapeutic intervention effects on renal function.
• It facilitates earlier and more accurate clinical decision-making in managing kidney diseases.
• Microcomputer implementation makes advanced statistical analysis accessible for routine clinical use.