Original Investigation
Pathogenesis and Treatment of Kidney Disease
Detection and Awareness of Moderate to Advanced CKD by Primary Care Practitioners: A Cross-sectional Study From Italy

https://doi.org/10.1053/j.ajkd.2008.03.002Get rights and content

Background

Chronic kidney disease (CKD) is a strong independent predictor of cardiovascular disease. Although general practitioners (GPs) represent the first line for identification of these high-risk patients, their diagnostic approach to CKD is ill defined.

Study Design

Cross-sectional evaluation of database of Italian GPs.

Setting & Participants

Representative sample of adult Italian population regularly followed up by GPs in 2003.

Outcomes

Frequency of serum creatinine testing, prevalence of CKD (estimated glomerular filtration rate [eGFR] < 60 mL/min/1.73 m2), awareness of CKD assessed from use of diagnostic codes (Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM]) for CKD, and referral to nephrologists.

Results

Of 451,548 individuals in the entire practice population, only 77,630 (17.2%) underwent serum creatinine testing. Female sex (odds ratio [OR], 1.09; 95% confidence interval [CI], 1.06 to 1.12), advanced age (OR, 2.70; 95% CI, 2.63 to 2.78), diabetes (OR, 1.31; 95% CI, 1.20 to 1.42), hypertension (OR, 1.10; 95% CI, 1.02 to 1.19), autoimmune diseases (OR, 1.42; 95% CI, 1.11 to 1.82), and recurrent urinary tract infections (OR, 1.63; 95% CI, 1.10 to 2.42) were all associated with serum creatinine testing. Conversely, use of either nonsteroidal anti-inflammatory drugs (OR, 1.03; 95% CI, 0.89 to 1.21) or aminoglycosides or contrast media (OR, 0.78; 95% CI, 0.54 to 1.14) was not associated with serum creatinine testing. In the subgroup with serum creatinine data, the age-adjusted prevalence of CKD was 9.33% (11.93% in women, 6.49% in men). However, in patients with eGFR less than 60 mL/min/1.73 m2, serum creatinine values were apparently normal (<1.2 mg/dL in women, <1.4 mg/dL in men) in 54%, and GPs used ICD-9-CM codes for CKD in only 15.2%. Referral to nephrologists ranged from 4.9% for patients with eGFR of 59 to 30 mL/min/1.73 m2 to 55.7% for those with eGFR less than 30 mL/min/1.73 m2.

Limitations

The prevalence of decreased kidney function may be overestimated because of the more frequent serum creatinine testing in sicker individuals and lack of creatinine calibration.

Conclusions

In primary care, CKD stages 3 to 5 are frequent, but its awareness is scarce because of limited rates of serum creatinine testing and difficulty recognizing decreased eGFR in the absence of increased serum creatinine testing.

Section snippets

Data Source

Primary care–based data were obtained by the Health Search/Thales Database (HSD), set up by the Italian College of General Practitioners in 1998. It includes a large and representative sample of the Italian population and has the primary aim of carrying out observational studies of the incidence and prevalence of chronic diseases. GPs are recruited to include a number of patients proportional to the size of the population of their respective geographic locations. At the time of this study, the

Patient Characteristics

Practices of the 320 selected GPs covered a total of 541,351 Italian adults in 2003. We excluded 89,803 individuals with inadequate (<12 months) follow-up in primary care offices. Clinical characteristics of the 451,548 study participants of the entire practice population are listed in Table 1. The entire practice population was representative of the Italian population, exemplified by the age distribution of the HSD, which was similar to that of study participants included in the Italian Census

Discussion

This study evaluates the prevalence of decreased kidney function (CKD stages 3 to 5) in a large and representative sample of the Italian population followed up in primary care. We found that the age-standardized prevalence of eGFR less than 60 mL/min/1.73 m2 (<1.00 mL/s/1.73 m2) is 9.3% (11.9% in women, 6.5% in men), with the greatest rates detected in the elderly (27.8%). These data cannot be compared with prevalence estimates in the general population. Our aim is to explore the diagnostic

Acknowledgements

This study is part of a collaboration program between the Italian Society of Nephrology and the Italian College of General Practitioners.

Support: This project has been supported by a grant from the Italian Society of Nephrology in 2005 (President: F.P. Schena).

Financial Disclosure: None.

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