This survey questionnaire comprises two main parts, namely "Opinions of all respondents" and "Opinions of urinary stone patients and their families". Key findings are summarized below. Cross-references can be made with the tables in Appendix 2.
(I) Opinions of all respondents
The survey began by asking all respondents their own daily consumption of drinking fluid, and they were prompted to answer in quantities of 250ml standard paper packages. Findings showed that, excluding those who could not give definite answers, on average each would drink volumes of 6 paper packages, or 1,500ml of fluid per day (standard error: 23ml). Grouped into categorical answers, 11% of the respondents would drink less than 1,000ml of fluid each day while 30% said "1,000-1,499ml" and 27% said "1,500-1,999ml". Those who said "2,000-2,499ml" accounted for 20% of the total sample. Another 9% reported that their daily drinking fluid consumption amounted to as high as "over 2,500ml". Since a person on average needs to consume at least 2,000ml of drinking fluid per day in order to reduce the risk of urinary stone formation (information provided by the Hong Kong Society of Endourology), our survey showed that only 28% of the respondents drink sufficient amount of fluid each day (i.e. drinking at least 8 packages of 250ml fluid). However, a significant proportion of respondents, at 68%, failed to reach this standard (Table 3).
The survey then further gauged respondents' knowledge of the minimal amount of fluid to be taken in each day for reducing urinary stone formation rate. Results showed that 5% of them considered "less than 1,000ml" as the daily minimum requirement while those who said "1,000-1,499ml" and "1,500-1,999ml" accounted for 15% and 11% of the total sample respectively. Meanwhile, 37% thought the minimal intake was "2,000-2,499ml" while 6% said "2,500ml or above". Another 24% said they did not know. Judged according to the standard recommended by the Hong Kong Society of Endourology (point 3.1), only 43% of the respondents had the correct concept that the minimum amount of drinking fluid for avoiding stone formation should be at least 2,000ml, 31% gave a wrong answer while 24% admitted ignorance (Table 4).
At the same time, the majority (66%) of the respondents reported that they were not aware of which dietary ingredients might predispose the formation of urinary stone. For those who were aware, "salty food/food with high sodium" topped the list with 9%, followed by "tofu" (5%) while "fatty food" (3%) and "food with high calcium" (3%) came in third and fourth places. Besides "salty food/food with high sodium", this survey found out that very few respondents could correctly point out that "spinach", "tea and milk tea", "coffee" (each with 2%), "other meats", "sweet food", "nuts and peanuts", "beef" (each with 1%), and "chocolate" (less than 1%) were indeed the diets that predispose the formation of urinary stone (information provided by the Hong Kong Society of Endourology, Table 5 and 5a).
Findings also showed that 37% of the respondents did not consider that restricting calcium intake, meaning not eating too much food with calcium in it, would be good for prevention of urinary stone disease. According to the Hong Kong Society of Endourology, this is the correct answer. The percentage was just slightly higher than those who hold the opposite view (33%) and those who failed to make a judgement (30%, Table 6).
The survey continued to ask the respondents whether holding urine in bladder would be a cause of urinary stone disease. Findings showed that 64% believed so, while 24% said the opposite and 13% did not give a definite answer. According to the Hong Kong Society of Endourology, the correct answer is "no", so only 24% got it right. Most people held the wrong view that holding urine in bladder would increase the chance of having urinary stone disease (Table 7).
As for who should be consulted for treatment if a person had urinary stone disease, about half (48%) of the respondents considered "urologist" to be the best choice among all medical practitioners. "Internalist" and "renal physician" came second and third, attaining 28% and 15% respectively. Other more common answers included "general surgeon" (7%), "general practitioner" (6%), "traditional Chinese medical practitioner" (2%), etc. Yet, 18% did not have an idea (Table 8 and 8a).
Before going into the second part, the survey tried to identify whether the respondents or their core family member had ever had urinary stone disease before. Findings showed that 90% of the respondents gave a negative response. On the other hand, 7% said their core family member had this disease while 2% admitted they were patients of urinary stone disease or had the disease but cured (Table 9).
(II) Opinions of urinary stone patients or their family members
The second part mainly focused on the urinary stone patients or their family members only and the valid base was 95 for this part. Results showed that nearly one-third (32%) had consulted "urologist" while 21% visited a "government doctor" but without knowing the doctor's specialty. Other common answers included "general practitioner" (11%), "general surgeon" (10%), "internalist" (9%) and "renal physician" (6%). About 4% said they had not consulted any doctor at all while 12% did not give a definite answer (Table 10 and 10a).
As regards the methods used to diagnosis urinary stone, findings showed that "Plain X-ray" was the most popular method accounting for 41% of these respondents. "Ultrasound" came second with 26%, while 9% used "Intravenous Pyelogram (IVP)" and 7% used "CT scan". Those who had forgotten or did not know accounted for 29% of the sub-sample (Table 11 and 11a).
In terms of treatment of urinary stone, 30% of the patients or their family received "Extracorporeal Shock Wave Lithotripsy (ESWL)" as treatment for the stone whereas a respective of 26% and 25% were treated by "open surgery" and "frequent check-up". Other treatments received included "drugs" (22%), "Chinese herb" (12%) and "operation with endoscopes" (9%). However, 5% said they were not willing to receive treatment, 3% did not consult any doctor after the diagnosis and 9% did not remember (Table 12).
As for the 79 patients who had received treatment, the majority (71%) reported that the whole stone was cleared while 12% only managed to clear part of it and 9% claimed the treatment had failed and the stone was not cleared (Table 13).
The last part of this survey measured patients' readiness to recommend their doctor to friends who have the same illness. Results revealed that 16% of the patients or their family members said they would definitely recommend their doctor to others, while the same percentage of patients said "maybe". Interestingly, 34% inclined not to do so and another 34% failed to give a definite answer (Table 14).
For cross-tabulation analyses of each question based on the urinary stone patients or their family members, please refer to Tables 15 to 25 of Appendix 2. Because the sample size of actual patients was small, our cross-tabulation analyses have not yielded significant findings. Clinical studies of real patients may be more useful in this aspect.
(IV) Concluding Remarks
This is a general opinion study of the Hong Kong population, with very few actual patients with urinary stone included in the random sample. As such, findings from this study may be more useful in planning for public campaigns to promote public health by educating people on how to prevent urinary stone, rather than in pinning down patients' characteristics.
According to our findings, less than half of the population knew that one must drink at least 2,000ml fluid every day in order to avoid the formation of urinary stone, over two-thirds actually failed to drink this much every day. Moreover, only slightly over one-third knew that restricting calcium intake is not a preventive measure, while only one-quarter knew that holding urine in bladder would not increase the chance of having urinary stone.
We will not repeat the opinions of urinary stone patients and their family members here, since the number of patients in our sample is small, and clinical studies may be more telling in this aspect. There should be no doubt, however, that whatever we do in educating the public on the formation and prevention of urinary stones, the patients and their families would also benefit. This opinion survey itself would hopefully become one part of this public education campaign.