the prevalence of kidney stones in the united states has risen steadily in recent years and correlates with population dietary changes .
relative dietary intake of fluid , sodium , calcium , oxalate , citrate , and animal - based proteins has a marked influence on stone risk .
accordingly , an efficient assessment of a patient 's nutritional intake is important for the urologist and may enable an informed assessment and guided recommendations .
the traditional office based interview may not adequately assess the patient 's nutritional intake , due to time constraints and the detailed nature of a nutritional history .
furthermore , biases may exist both in how a patient wishes to represent themselves , and in how the practitioner presents a question .
we sought to determine if a physician 's impression of a patient 's dietary intake was dependent on the medium through which they obtained the nutritional data .
a typical office interview was compared to information obtained via a computerized clinical decision support system ( cdss ) , which presented a food frequency questionnaire ( ffq ) .
furthermore , the urologists made recommendations for dietary intervention based on the information ascertained via each method .
each patient completed : ( 1 ) an office - based interview with one of two fellowship - trained endourologists , and ( 2 ) a ffq administered via a cdss , presented on an ipad .
each urologist made two separate assessments via a likert - scale - based survey of the significance of a patient 's nutritional ( nutritional impact score ) and hydration factors ( hydration impact score ) as they pertained to stone disease ( fig .
each assessment was followed by specific recommendations , such as reducing sodium intake , reducing animal protein intake , and increasing fluid intake .
the first assessment ( pre - ffq ) was made after the office - based interview with the patient but without reviewing the results of the ffq .
the second assessment ( post - ffq ) was made after reviewing the patient 's ffq results .
if the urologist modified the nutritional impact score , hydration impact score , or treatment recommendations from the first assessment to the second , we assumed that the ffq results caused the urologist to believe that nutrition had a greater or lesser impact on the patient 's stone disease than previously assessed by the office - based interview .
the ffq used in this study is an 88-question nutritional survey that is similar to prior ffqs that have been validated by previous analyses for accurate assessment of a patient 's dietary habits . using the ffq , our patients recorded nutritional intake of those foods providing substantial quantities of the following : oxalate , animal - based protein , sodium , and calcium .
intake of fruits and vegetables , fluids , and nutritional supplements was also assessed ( fig .
questionnaire results were entered in the ffq 's algorithm , which generated numerical scores corresponding to patient 's relative intake in each of the following domains : oxalate , calcium , sodium , purine , and fluids . for each patient , we compared pre - ffq nutritional impact score , hydration impact score , and treatment recommendations to respective post - ffq data points .
our results were coded into the following binary variables , detailing the presence or absence of : increase in diet score , increase in hydration impact score , any change in treatment recommendations , addition of at least one treatment recommendation , and subtraction of at least one treatment recommendation .
a multivariate logistic regression model was fit to determine the impact of the numerical results of each domain in the ffq ( oxalate , calcium , sodium , purine , and fluids ) and the aforementioned binary variables .
each patient completed : ( 1 ) an office - based interview with one of two fellowship - trained endourologists , and ( 2 ) a ffq administered via a cdss , presented on an ipad .
each urologist made two separate assessments via a likert - scale - based survey of the significance of a patient 's nutritional ( nutritional impact score ) and hydration factors ( hydration impact score ) as they pertained to stone disease ( fig .
each assessment was followed by specific recommendations , such as reducing sodium intake , reducing animal protein intake , and increasing fluid intake .
the first assessment ( pre - ffq ) was made after the office - based interview with the patient but without reviewing the results of the ffq .
the second assessment ( post - ffq ) was made after reviewing the patient 's ffq results .
if the urologist modified the nutritional impact score , hydration impact score , or treatment recommendations from the first assessment to the second , we assumed that the ffq results caused the urologist to believe that nutrition had a greater or lesser impact on the patient 's stone disease than previously assessed by the office - based interview .
the ffq used in this study is an 88-question nutritional survey that is similar to prior ffqs that have been validated by previous analyses for accurate assessment of a patient 's dietary habits . using the ffq , our patients recorded nutritional intake of those foods providing substantial quantities of the following : oxalate , animal - based protein , sodium , and calcium .
intake of fruits and vegetables , fluids , and nutritional supplements was also assessed ( fig .
questionnaire results were entered in the ffq 's algorithm , which generated numerical scores corresponding to patient 's relative intake in each of the following domains : oxalate , calcium , sodium , purine , and fluids .
for each patient , we compared pre - ffq nutritional impact score , hydration impact score , and treatment recommendations to respective post - ffq data points .
our results were coded into the following binary variables , detailing the presence or absence of : increase in diet score , increase in hydration impact score , any change in treatment recommendations , addition of at least one treatment recommendation , and subtraction of at least one treatment recommendation .
a multivariate logistic regression model was fit to determine the impact of the numerical results of each domain in the ffq ( oxalate , calcium , sodium , purine , and fluids ) and the aforementioned binary variables .
between the 2 urologists in the study , there was no significant difference in the average nutritional impact scores or average the hydration impact scores assigned . from pre - ffq
to post - ffq , the urologist was more likely to increase the nutritional impact score if the patient had higher ffq scores for sodium ( odds ratio [ or ] , 1.02 ; p=0.02 ) or fluids ( or , 1.03 , p=0.04 ) . in other words
, the physician interpreted a greater contribution of diet to the patient 's stone disease when the ffq indicated higher sodium or fluid intake ( table 2 ) .
there was no difference in hydration score rendered by the physician for patients who consumed increased oxalate , calcium , sodium , purine , or fluids ( table 3 ) .
a higher ffq score for oxalate was positively associated with the addition of at least one treatment recommendation ( or , 1.07 ; p=0.02 ) ( table 4 ) .
stone disease is among the most common and costly urological conditions , with a lifetime prevalence of approximately 9% , and 5-year recurrence rates approaching 50% . in the united states alone ,
the economic burden of stone disease has been estimated to be over $ 2 billion annually .
previous studies have underscored the impact of diet on stone formation and the role of dietary interventions in prevention of stone disease .
our study revealed that using a ffq to obtain the diet history impacted how urologists perceived the effects of diet and hydration on stone disease , as well as how urologists treated the stone disease .
therefore , it is important for the urologist to effectively and expeditiously obtain a thorough diet history .
certainly , the modern urologist experiences logistical and time constraints in his or her busy clinical practice . additionally , some patients may alter their responses to dietary questions in an attempt to represent their habits more favorably .
furthermore , even skilled endourologists and stone experts may not use the most effective questions to obtain the information necessary .
finally , a comprehensive stone clinic , complete with a dietician is favorable , but not feasible in every practice setting .
previous authors have found the ffq to be an effective tool for obtaining an accurate and objective diet history . as for the method of delivering the ffq
, we believe that the computerized cdss provides physicians with a relatively bias - free mode of data collection as well as standardized evaluations of the data delivered in a timely fashion .
in other medical applications , the cdss has been shown to improve practitioner performance and patient care , for instance , by reducing medication errors . in the present study
, we found that the use of the ffq as a cdss can significantly alter the how the endourologist assesses the significance of dietary factors on a patient 's stone disease .
moreover , the recommended dietary interventions can change based on the results of the ffq . in our urolithiasis clinic ,
nearly all of the patients ( 75 of 76 ) were willing to use the ffq .
these findings suggest that the addition of the ffq to the 24-hour urine collection and other components of the comprehensive stone evaluation may alter the assessment and plan for these patients .
the major limitation of our study is that we did not determine if use of the ffq leads to improved patient outcomes , such as decreased recurrence rates or increased patient satisfaction .
future studies may be developed to link the use of the ffq to improved outcomes or patient encounters .
while our study may not yet translate into improved patient outcomes , certainly others have shown that the use of cdss can improve efficiency .
it is reasonable to hypothesize that improving efficiency may be a key component in improving patient outcomes .
other studies have also shown that ffqs can play an integral role in assessing urolithiasis patients , especially in a multidisciplinary setting , where a patient 's diet may be a key focus in stone prevention .
while our ffq was reasonably detailed , others have been able to streamline a more lengthy diet questionnaire into a more compact rapid food screener . in regards to assessing renal acid load in stone formers ,
his goal was to make this rapid assessment equivalent to a more lengthy diet questionnaire . in a follow - up study , patients were asked to complete both of these questionnaires , and their lake score assessment appeared as good as a lengthier questionnaire in determining renal acid load . while this particular study looked at a different aspect of stone disease , it appears that endourologists are attempting to gain detailed dietary information from their patients while continuing to improve efficiency and streamline their stone clinics .
certainly these approaches may prove worthwhile as we continue to develop this tool in our urolithiasis clinic .
we hope that our efforts may ultimately improve the efficiency and quality of care of our endourology patients .
given the wide body of evidence supporting the use of dietary interventions in preventing stone recurrence , it is reasonable to hypothesize that recommendations made with potentially more complete and accurate data , obtained using the ffq , would confer improved outcomes .
randomized - controlled trials are necessary to evaluate the impact of utilizing the ffq as a cdss on stone patients to patient outcomes , such as recurrence rates , quality of life , and satisfaction with the clinical experience .
a self - reported , electronic version of the ffq may be helpful in the efficient assessment and counseling of patients with stone disease . with prior comprehensive knowledge of a patient 's nutritional intake ,
the urologist may be afforded more time with which to counsel patients regarding intervention and nutritional intake .
 purposeto evaluate a physician 's impression of a urinary stone patient 's dietary intake and whether it was dependent on the medium through which the nutritional data were obtained . 
 furthermore , we sought to determine if using an electronic food frequency questionnaire ( ffq ) impacted dietary recommendations for these patients.materials and methodsseventy - six patients attended the stone clinic over a period of 6 weeks . 
 seventy - five gave consent for enrollment in our study . 
 patients completed an office - based interview with a fellowship - trained endourologist , and a ffq administered on an ipad . 
 the ffq assessed intake of various dietary components related to stone development , such as oxalate and calcium . 
 the urologists were blinded to the identity of patients ' ffq results . 
 based on the office - based interview and the ffq results , the urologists provided separate assessments of the impact of nutrition and hydration on the patient 's stone disease ( nutrition impact score and hydration impact score , respectively ) and treatment recommendations . 
 multivariate logistic regressions were used to compare pre - ffq data to post - ffq data.resultshigher ffq scores for sodium ( odds ratio [ or ] , 1.02 ; p=0.02 ) and fluids ( or , 1.03 , p=0.04 ) were associated with a higher nutritional impact score . none of the ffq parameters impacted hydration impact score . a higher ffq score for oxalate ( or , 1.07 ; p=0.02 ) was associated with the addition of at least one treatment recommendation.conclusionsinformation derived from a ffq can yield a significant impact on a physician 's assessment of stone risks and decision for management of stone disease . 