Introduction
Kidney stone disease (KSD) is a common problem, affecting approximately 10–15 % of people in Europe and North America [
1•]. In the USA, the lifetime prevalence for men is 12 %, and for women, it is 6 % [
2]. Stone formers are 50 % more likely to have a further stone in the following 5 years [
3]. Although some patients are asymptomatic with their KSD, many will have pain, urinary tract infection (UTI) or haematuria and may require multiple hospital admissions or multiple surgical procedures for this. This may also affect their renal function with an impact on their quality of life (QOL).
There are numerous ways to treat renal tract calculi, depending on their size, location, volume, anatomical factors and patient comorbidities. Historically, it was open surgical techniques; shock wave lithotripsy (SWL) was introduced in 1980, followed by percutaneous nephrolithotomy (PCNL) and subsequently endourological techniques with the popularisation of ureteroscopy (URS). After any one of these procedures, especially ureteroscopy, a ureteric stent may need to be placed. The presence of KSD, interventions for it and/or ureteric stents can all influence the QOL to varying degrees [
4‐
10].
Patients with KSD can have increased levels of bodily pain, depression, loss of days at work and increased anxiety and financial distress, leading to overall lower QOL scores [
11‐
15,
16••]. How KSD and its treatments affect QOL may affect patient or surgeon decisions regarding the management of their KSD [
15]. The impact of KSD on patients’ QOL is becoming increasingly important to consider, as the focus of treatment has shifted not just only from considering morbidity and mortality but also considering the impact on their QOL [
17‐
22,
23•].
Quality of life is a subjective experience and hence makes the effective measurement difficult. It is important to consider patients’ QOL, as it can help us understand how the disease affects their day to day living, and the personal burden of illness. This is not always related to the severity of their disease, by laboratory values or imaging, but by how the disease and possibly its treatment are perceived by the patient [
18]. There are many psychosocial factors that need to be taken into consideration as well as symptom-related aspects of QOL. Examples of these are financial difficulties, stresses from job, family and associated pain [
5]. There are a multitude of designed and validated tools used to measure this [
5‐
8]. It is important for patients to assess their own QOL, not for health professionals to try and assume what it might be. Measuring QOL is important as one of the aims of any treatment is for the patient to feel and function normally. Using the information gathered from QOL studies, patients can be better informed on their treatment options and how they may fair after different treatments. Over the last 30 years, improving patients QOL has become an increasingly important part of treatment, and therefore, many tools have been produced to measure this [
5‐
8]. However, there are currently no validated KSD-specific QOL tools available [
15].
We conducted a systematic review of literature to look at the tools used for measuring QOL and the aspects of patients QOL most affected by KSD.
Discussion
Findings of Our Study
Overall, seven of the nine studies demonstrated a lower QOL in patients with KSD. Bodily pain and general health was significantly lower in patients with KSD compared to their control groups. There seems to be a correlation between stone episodes and QOL, and this seems to improve with the passage of time. Similarly, previous surgical intervention seems to have a negative impact on their QOL, as compared to the control group.
Importance of Measuring QOL in KSD Patients
Patients with KSD tend to have a lower QOL even in the absence of stone episodes or interventions. It might reflect their previous experience of stone disease or an apprehension of the need for further treatment. Measurement of QOL is important to understand the impact of psychosocial and physical aspects of the disease. It can aid us in advising which management option may be more suitable for the individual. Only a longer-term follow-up over a few years would help us determine the time taken for the QOL domains to get back to baseline. QOL measurements also help us to evaluate and see ways in which we can improve our surgical choices or technique to improve patients’ QOL [
21].
Comparison and Outcomes of Different QOL Studies
There are a multitude of generic QOL tools; selecting a measure can be difficult, as there are so many to choose from [
4]. Examples of generic available measures are Short Form 36 (SF36) [
5], Hospital and Anxiety Depression Scale (HADS) [
6] and Profile of Mood States (POMS) [
7]. There is also a QOL tool for patients with a ureteric stent in situ, the ureteric stent specific questionnaire (USSQ) [
8]. The four different tools that where used in the literature in this review all have their own advantages and disadvantages that are summarised in Table
3. None of the tools used so far are perfect for assessing the QOL of patients with KSD. Large numbers of patients suffer with KSD [
1•,
2,
3], and it has a huge impact on a person’s QOL [
11‐
15,
16••,
18]. A disease-specific QOL tool that is universally used would be useful to measure and compare QOL in these patients.
Table 3
Advantages and disadvantages of current questionnaire used
| • Covers wide range on QOL domains • Widely used | • No KSD specific questions |
Winsicon QOL in stones [ 16••] | • Stone specific • Treatment specific | • Not validated • Large questionnaire • Not broken into domains • Difficult to analyse |
Emory stone questionnaire [ 15] | • Demographic specific • Stone specific | • Not a QOL measurement |
| • Specific for depression | • No QOL domains |
The most common QOL tool used in our literature review for patients with KSD was the SF-36. As the SF-36 is a generic questionnaire, it does not target symptoms specific to stone formers and may not be sensitive enough to measure their QOL accurately [
11]. However. when analysing the studies using the SF-36 questionnaire, we found a statistically significant difference in the bodily pain and general health sub domains (Table
2).
There are many disease-specific QOL tools [
25], although we could find none specifically designed for patients with KSD that had been widely validated. One study [
15] aimed to fill this gap and produce a tool (the Winsicon Stone Quality of life questionnaire), specifically for patients with KSD. They also looked at asymptomatic stone formers in a paper published in 2016, and they found that even if the person was not aware of having KSD, but did have stones, they still had a lower QOL in specific domains, particularly urinary frequency, urgency, anxiety or nervousness (
p = <0.027) [
22]. In the limitations of these two studies, the authors identified that further research into this area needs to include understanding the role of comorbidities and social economic status in patients with both symptomatic and asymptomatic stones, as well as identifying the need for multi-institutional testing of the WiSQoL questionnaire to validate it.
Limitations of the Study
The studies using the same QOL questionnaires did not assess the data in a similar fashion, or compared the patients QOL to the same ‘norm’. None of the studies made it clear if the patient was having an active stone at the time of questionnaire administration, or in the month prior (the SF-36 only measure QOL in the 31 days prior to completing the questionnaire). It is well recognised that recent procedures and ureteric stents lower patients’ QOL and to avoid bias, we did not include these studies in our review [
17].
Some of the other limitations are the lack of stone characteristics in the data provided, such as size, position and composition of stones. There were no randomised controlled trials and all studies were of level 2a/b evidence.
A number of confounding factors associated with KSD can also affect QOL of these patients. For example, obesity has been shown to lower QOL [
19] and is also known to be associated with stone formers. One of the studies demonstrated that QOL in stone formers was worse in women and in patients with high BMIs [
13]. Chronic diseases such as gout, diabetes, inflammatory bowel disease and bowel procedures are all associated with stone formation, but may themselves lower patients QOL [
20,
26,
27]. Other patient-related confounding factors that may impact on measurement of QOL includes difficulty completing the questionnaire, procedural and judgement issues. Even with these limitations, seven [
5,
12‐
15,
16••,
23•] out of the nine studies demonstrated lower QOL in patients with KSD.
Areas of Future Research
Areas of future research could include evaluating the WisQOL questionnaire over a larger and multi-institutional patient cohort. It would also be of benefit to look not just at health-related QOL, including the physical, mental and emotional burden of KSD to health, but also the financial impact, including the loss of earnings to the individual as well as the financial cost on the health service. Donnally et al. in their longitudinal evaluation of QOL using SF-36 found no significant changes in domains suggesting that a validated disease-specific questionnaire might be better in these patients [
11].
An important aspect of KSD is the affect to patients’ family and wider concept of management of other associated medical conditions either related to or contributing to KSD. Any QOL study is perhaps incomplete without addressing some of these factors. It is perhaps time that research and resource is allocated to generating patient-reported QOL outcome measures specific to KSD.
Conclusion
KSD affects QoL in most patients with most impact on bodily pain and general health domains. Compared to the scale of patients suffering from KSD, more work needs to be done in measuring QOL both in terms of ‘Stone specific’ QOL measuring tools and the quality/number of studies in this field.
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