Diagnostic performance and cost-effectiveness of portable digital pH meters and traditional dipsticks for urine pH monitoring in patients at risk of recurrent urolithiasis.

Introduction: Urolithiasis affects up to 10% of the population and recurs in more than 50% of cases within ten years. Urinary pH plays a pivotal role in stone prevention, but dipstick testing, the most commonly used method, lacks accuracy, precision and reliability. Only portable digital pH meters classified as medical devices offer superior accuracy, sensitivity, specificity, and resolution, enabling more reliable urinary pH monitoring than dipstick testing. Nevertheless, their comparative cost-effectiveness remains unclear.  Methods: we conducted a systematic review and cost-effectiveness analysis comparing a portable digital pH meter with dipsticks for urinary pH monitoring in recurrent stone formers. Following PrIsMA 2020 guidelines, studies reporting on accuracy, precision, or costs were included. Data were pooled using random-effects models. Cost estimates were derived from the European market sources and adjusted for inflation. Outcomes included analytical validity, cost per effective unit, number needed to treat (NNT), and cost per quality-adjusted life-year (QALy) gained.

Results: Thirteen studies involving 2,801 participants were included in the quantitative synthesis. The portable digital pH meter consistently outperformed dipsticks across all evaluated parameters, demonstrating higher explained variance (r2 0.97 vs 0.54), finer resolution (0.1 vs 0.5 pH units), and lower systematic bias (0.06 vs 0.36). The cost per effective unit was lowest for the portable digital pH meter (€ 179) compared with once-daily (€ 354) and twice-daily dipstick testing (€ 708). In compliance-adjusted models, the cost per lithiasis episode prevented was € 590 for the portable digital pH meter vs €1,169 and € 2.337 for dipsticks. In a simulated 1.,000-patient cohort, the portable digital pH meter yielded the lowest total costs (€ 601.376) and the greatest QALy gain (17.84), demonstrating a dominant result, being both more effective and less costly than all alternatives.

Conclusions: The portable digital pH meter demonstrated superior analytical performance and cost-effectiveness compared with dipsticks for urinary pH monitoring. Its broader implementation may enhance preventive strategies, reduce stone recurrence, and decrease the overall healthcare burden associated with recurrent urolithiasis. Considering these findings, the portable digital pH meters may warrant consideration for inclusion in major clinical guidelines on urolithiasis and for reimbursement by healthcare systems, potentially supporting their broader adoption in clinical practice.