An International Study of Variation in Attitudes to Kidney Biopsy Practice

Key Points Attitudes on kidney biopsy practice vary significantly across the world. Male clinicians, younger clinicians, and individuals who perform biopsies more frequently had an increased propensity to recommend a kidney biopsy. Kidney biopsy was most often recommended in the setting of higher proteinuria levels and preserved kidney function. Background A kidney biopsy is an essential investigation for diagnosis but is invasive and associated with complications. Delaying or missing the opportunity to diagnose kidney disease could result in adverse patient outcomes. The aim of this study was to examine attitudes to kidney biopsy across the world. Methods An online questionnaire for nephrologists was designed on the basis of the existing literature with input from patients. Anonymized data were collected on individual and institutional demographics, indications and contraindications for biopsy, and attitudes and barriers to access. A propensity-to-biopsy score was generated from responses, which allowed clinicians to compare their practice with international colleagues. A higher score was associated with an increased likelihood of recommending biopsy. The questionnaire was disseminated through international nephrology societies, including the National Kidney Foundation, and by social media. Results Participants responding to the questionnaire included 1181 clinicians from 83 countries, making it the largest international study in this area to date. The propensity-to-biopsy scores were significantly different between the 13 countries with over 20 clinicians participating ( P < 0.001) and was highest in Mexico and lowest in the Philippines. Kidney biopsy was most often recommended in patients with higher proteinuria levels and most often avoided in patients with small kidneys. An adjusted linear regression model demonstrated that a significantly higher propensity-to-biopsy score was found in male clinicians, younger clinicians, frequent performers of kidney biopsy, increased job seniority, and larger institution size ( P = 0.05). Conclusions Kidney biopsy practice is varied internationally and is subject to human and systemic factors. Further research is required to understand the variances behind clinical decision making.