Benchmarking Rapid Screening Kits versus Iodometric Titration for Iodine Quantification in Household Salt

Area of Science:

• Public Health Nutrition
• Analytical Chemistry
• Diagnostic Test Evaluation

Background:

• Iodine deficiency remains a global public health concern, necessitating accurate monitoring of iodized salt.
• Challenges persist in monitoring iodine content in household salt, even with universal salt iodization programs.
• This study addresses the need for reliable assessment methods in Razavi Khorasan Province.

Purpose of the Study:

• To evaluate the accuracy and precision of rapid screening kits for household salt iodine quantification.
• To compare the performance of rapid screening kits against iodometric titration, the established gold standard.
• To inform strategies for improving iodine content monitoring in the region.

Main Methods:

• A cross-sectional study involving 153 household salt samples collected in 2024.
• Iodine concentration measured using the Waheb iodine test kit and compared with iodometric titration.
• Statistical analysis included sensitivity, specificity, predictive values, and Cohen's kappa for method agreement.

Main Results:

• Rapid screening kits yielded a mean iodine concentration of 35.75 µg/g, significantly lower than iodometric titration (58.38 µg/g).
• The kits showed high sensitivity (84.91%) but very low specificity (20.00%).
• Agreement between rapid kits and iodometric titration was poor (Cohen's kappa = 0.037).

Conclusions:

• Rapid screening kits demonstrate limited reliability for accurately assessing household salt iodine levels.
• The observed discrepancies highlight a need for enhanced quality control measures.
• Development of more accurate rapid testing methods is crucial for effective iodine deficiency prevention and control.