Dipstick diagnosis: how accurate is it for cystitis ?

The accuracy of dipstick diagnosis for common urinary infections will be examined over the next four years by a research team at the University of Southampton.

Funded by the Department of Health, the research aims to find out if diagnosis of infections such as cystitis can be made quickly using a dipstick, without waiting for laboratory test results, and whether this then leads to more effective treatment of the problem. The study, led by Dr Paul Little and Dr Helen Smith of the University's Primary Medical Care group, will be the first to investigate how accurate dipsticks are in diagnosing infections in a General Practice setting.

The first part of the study will aim to check the samples of 4000 patients from GP practices across southern England who see their doctor with a suspected urinary infection.

The urine samples will be tested with a dipstick, and then in a laboratory, and the results of both tests compared to establish the accuracy of the dipstick diagnosis.

Other indicators may also be important in making a diagnosis, such as the odour or cloudiness of the sample, and the severity and length of time an infection has lasted. These will also be assessed to determine if accurate diagnosis can be made using only these symptoms, or by combining these with the dipstick results.

The second part of the study will look at how useful the dipstick results are in guiding the treatment or advice given to patients. Patients will be asked to keep a diary of symptoms and actions taken to alleviate their condition, to establish whether the immediate use of antibiotics, the use of antibiotics following a lab result or the use of self-help measures resulted in the best resolution of the problem.

Dr Little, a Senior Lecturer and Medical Research Council Clinician Scientist, said: "Acute urinary tract infections are some of the commonest but least researched infections in general practice and dipsticks could potentially make a diagnosis in many cases. We just need to find out whether using dipsticks and simple observations during a visit to your local doctor can result in a quicker resolution of the symptoms for many patients."

Dipstick diagnosis alone is most likely to be useful in testing non-pregnant women with urinary infections, since in other groups of sufferers (men, children and pregnant women), a urinary infection may signal something more serious which must be checked through laboratory testing.

The research is being led by the Primary Medical Care group at the University of Southampton, but also involves collaboration with the Public Health Laboratory Service and researchers at the University of Oxford.