In urology, a frequently used questionnaire to objectify subjective symptoms is the International Prostate Symptom Score (IPSS): 7 questions evaluate LUTS and 1 question addresses quality of life (QOL). 
Several studies reveal difficulties with completing this questionnaire. To fill out IPSS correctly, patients need adequate health and literate skills. However, these skills are insufficient in up to 28% of people in the Netherlands, 50% in the US and 62% in eastern Europe. Thus, visual alternatives were designed: the South African Visual Prostate Symptom Score (VPSS) and the French Score Visuel Prostatique en Images (SVPI). See Figure.

For the first time, a qualitative study was performed in which participants filled out either the IPSS or one of the alternative forms while thinking aloud. Aim was to gain insight in the nature of comprehensibility problems. Based on the results of this analysis we developed a new questionnaire.

Men of 40 years and older who had not previously filled out IPSS, VPSS or SVPI participated. To evaluate their health literacy status, participants completed the validated Set of Brief Screening Questions. Next, they were asked to fill out one of the three forms while thinking aloud, without time limitation nor help. Finally, an interview took place. Problems during filling out, the most probable causes and the participants’ remarks were scored. 
Each form was tested by participants with adequate health literacy skills (AHLS) and by participants with limited skills (LHLS). Inclusion of participants of both groups continued until no new insights were obtained per form.
Random distribution of the forms, interviewing and scoring were done by one researcher and checked by a second one. After the interviews, problems during filling out were evaluated and the participants’ comments were processed. Based on these outcomes, a new questionnaire was developed. This questionnaire was evaluated concordantly by subjects with AHLS or LHLS and adjusted in a few cycles until no new insights were gained, resulting in the definitive form: the Dutch Reduced Illustrated Prostate Symptom Score (DRIPSS, see Figure).

Problems during filling out and their causes are shown for each individual question of the 3 forms in the Table.

While filling out IPSS, the 23 participants (med. age 72 (41-82 yrs)) often showed difficulties understanding the terms ‘past month’, ‘urinary stream’ and ‘weak’. The table design resulted in frequently filling out numeric values instead of using the answer options at top of the column, especially in the 7 LHLS-participants. Question 7 however is included in the table and should be answered by numeric values. The QOL-question was often overlooked by both groups by its isolated position.
Participants from both groups mentioned the complicated answer options (especially ‘less then 1 in 5 times’) and the reference period of 1 month. 
One AHLS and 4 LHLS-participants considered the questionnaire more difficult than other medical forms. Three AHLS and 4 LHLS-participants wished for an introduction in clear language. Almost all participants would have given the same answers filling out the form outside this test situation. Only in the LHLS-group, 1 participant said that he would normally fill out the questions he left open in the test situation, despite not clear what is being asked. 

While filling out VPSS, which consists of 4 questions with only visuals and no text, the 21 participants (med. age 69 (43-85 yrs)) often had problems understanding the first visual for daily micturition, leading to answers about mictions during work hours or only in the afternoon. Frequently, question 1 was only understood after filling in question 2. One participant missed the answer option ‘no nycturia’ in question 2. Question 3 lead to confusion caused by presenting the lowest score under the best urine stream and the highest score under the worst. The last visual proved to be unclear, leading to a variety of answers because of very different interpretations of what was asked. 
Six out of 15 AHLS-participants and 3 men in the LHLS-group considered the questionnaire more difficult than other medical forms. Four AHLS and 4 LHLS-participants would have appreciated an introduction in clear language. No participant would have given different answers when filling out the form outside this test situation.

SVPI texts were translated into Dutch and backtranslated by 3 professional translators. The 5 visual questions, each with a verbal explanation, did not cause any comprehension problems amongst the 21 participants (med. age 65 (40-78 yrs)) as far as questions 1 and 2 were concerned. Question 3 caused difficulties understanding the alarm sign at the side of least urgency. The answer option for the least urgency a few times was not interpreted as such due to the red stripe through it. Question 4 lead to confusion because of the lowest score under the best urine stream and the highest score under the worst, with the numbers in descending order. Question 5 proved to be clear, although the figure in front was interpreted as an answer option a few times.
In the interviews, participants mentioned the visual format of question 4 was difficult to understand. Only 2 out of 16 AHLS-participants, found the questionnaire difficult compared to other medical ones. Two men, also both AHLS-participants, would have appreciated an introduction in clear language. No participant would have given different answers when filling out the form outside this test situation.

Although best understood, the SVPI still left room for improvement. We developed an alternative form, elaborating on this SVPI. Based on given comments the print was made larger for better readability and figures in front of question 3 and 5 were removed. The answer option for ‘least urgency’ was changed into a person standing still. Question 4 was changed to the figure of VPSS in mirrored position and numbers were left out. A comparable evaluating qualitative study with 16 participants with AHLS (6) and LHLS (10) was performed (med. age 64.5 (45-76 yrs)). Comments were processed: answer boxes were inserted, verbal questions were placed above the visuals instead of below them and the box including question 4 was made as big as the other boxes. DRIPSS was retested until no new insights were obtained.

In our qualitative study we obtained insight in the comprehensibility problems of a frequently used questionnaire, something a quantitative study can’t do. IPSS proved difficult to understand by the table design and difficult answer options, for men with AHLS but more so for many men with LHLS. This questions the reliability of obtained scores. The completely visual VPSS also proved hard to understand: unclear what is being asked for, it leads to answers on different interpretations of the question. SVPI showed a good balance between visuals and short verbal questions but nevertheless received some negative comments. Our qualitative study design was extremely useful to obtain insight to develop a modificated version that will lead to less comprehension problems: the Dutch Reduced Illustrated Prostate Symptom Score (DRIPSS).

The frequently used IPSS is difficult to understand by a large amount of men, questioning reliability. Figurative alternatives are better comprehended especially when combined with short textual questions. Based on the results of our qualitative study, we made a redesign well understood by participants with adequate ánd limited literacy skills: the DRIPSS. Next step is validation for IPSS and flowmetry to justify use in (Dutch) urological practice.