We asked patients enrolled in both groups to rate the severity of urinary dysuria, urgency, frequency, function, and how they generally felt about their symptoms. Each was rated on a 10-point scale (10 was most severe). The telephone management patients were given a prescription for sulfamethoxazole/trimethoprim (800 mg/160 mg) twice daily for 7 days. If the patient was allergic to sulfa, she received a prescription for nitrofurantoin 100 mg twice daily for 7 days. Patients were required to have a urinalysis and urine culture before receiving the prescription. We asked the health care providers of the control patients to use their usual management strategies. The control group patients were also required to have a urinalysis and urine culture.
A nurse telephoned all women in both groups for follow-up 3 and 10 days after the time of enrollment. During these telephone calls we assessed patient status (including symptom scores and patient satisfaction) and whether the patient sought care with any practitioner since the initial time of enrollment. If UTI symptoms were still evident at either the 3- or 10-day follow-up, the patient was asked to make an appointment to see her practitioner. We recorded start and stop times for all interviews to assist in estimating and comparing costs of care for the 2 groups.
Primary Outcomes
The primary outcomes for our study were the UTI score and overall evaluation rating (OER)6 of the treatment experience. The UTI score is the sum of the ratings of severity of dysuria, urgency, frequency, function, and general symptoms (range=0-50). Since the UTI score has not been previously used, we pilot tested it on 20 women. These same women were reevaluated 2 to 3 days later. Test-retest reliability (measured by the overall correlation between the same items asked on 2 separate occasions with the order of questions changed) was 0.98. Validity (measured by the correlation coefficient between specific questions and a global question for the episode) was 0.52 for burning, 0.89 for frequency, 0.95 for urgency, 0.86 for interference with activities of daily living, and -0.76 for the actual interval between urination (smaller interval associated with greater overall episode severity).
The OER consisted of 2 questions about the overall quality of care and the outcome of care. Each question—answered as poor, fair, good, very good, or excellent—was scored from 1 to 5, respectively. The OER, a validated score,6 is a simple sum of the scores for these items (range 2-10, not normally distributed). Also, we asked the women about their overall satisfaction on a 5-point Likert scale.
Secondary Outcomes
We also evaluated urine culture results. We defined a negative culture as one with either no growth or less than 1000 colony-forming units. A positive culture had any growth of a single organism. A contaminated specimen (mixed flora) was rated as a negative culture, since this is how these are usually handled clinically.
Statistical Analysis
The data were entered into a database, and all entries were double-checked by one of the investigators for transcription errors. We analyzed the data using SAS software (version 7, SAS Institute, Cary, NC). Continuous variables (age, time variables, UTI score) were compared by treatment group using unpaired Student t tests. We used the Shapiro-Wilk test and the Kolmogorov-Smirnov test to confirm that the UTI score and changes in that score between assessments were normally distributed. We compared categorical variables (resolution of symptoms, culture results) by treatment group using a chi-square. We used Wilcoxon rank sum tests to compare ordinal data (OER) between the treatment groups.
For all sample size estimations we wanted to achieve 80% power with two-sided a of 0.05. To detect a 5-point difference in the UTI score, with an estimated a priori standard deviation (SD) of 5, we calculated that 16 subjects in each group are needed (21 for 90% power). With an SD of 7.5, 36 subjects in each group are needed. For patient satisfaction (OER), we estimated a priori that we would need 15 subjects in each group (19 for 90% power) to detect a 1-point difference with an estimated mean of 3.9 and a SD of 0.95.
Results
We identified 201 women with suspected UTIs of whom 99 were not eligible. Of the 102 eligible women, 30 declined to participate. We randomized 36 women to office care (control group) and 36 to telephone management. The subjects were predominantly white (n=62, 86%) and young (mean age=36.6 years, SD=12.3). Five patients had no culture results. Of the 67 remaining cultures, 4 (6%) were contaminated specimens, 20 (29.8%) had negative cultures, and 43 (64.2%) had positive cultures. Of the positive cultures, 34 (79.1%) grew Escherichia coli. Twenty-three of 34 (67.6%) cultures in the control group were positive compared with 20 of 33 (60.6%) in the telephone group (chi-square=0.3611; P=.55).