Likewise, consultation of the general practitioner (GP) and GP policy are subjects of discussion. In the Netherlands, men who develop lower urinary tract symptoms (LUTS) first consult their GP for medical care. Improved knowledge of the determinants of GP consultation in men with LUTS will contribute to an appropriate use of health care focused on the needs of elderly men. Previously studied factors that differed between men who sought medical care for LUTS and those who did not are retirement [2], scores on urinary symptom questionnaires [3], [4], being worried and embarrassed about urinary (dys)function [4], social influences [5], fear of cancer or surgery [6], and the patient's perception of the ability of the care provider [7]. These studies mostly investigated a specific factor of interest and were not prospective; thus, their prognostic value is limited. We conducted a longitudinal, population-based study focusing on symptom severity, age, and other important factors such as quality of life (QOL), urologic parameters (prostate volume, postvoid residual urine volume, and maximum urinary flow rate [Qmax]), lifestyle (smoking behaviour and drinking habits), and education. The present study aimed to determine which of these determinants predict seeking of primary care among men with LUTS.
2. Methods
2.1. Study design
The design of the Krimpen study of male urogenital tract problems and general health status has been described in detail [8]. Briefly, the Krimpen study involved men aged 50–78 yr living in a Dutch municipality near Rotterdam. Men without radical prostatectomy, prostate or bladder cancer, neurogenic bladder disease, or negative advice from their GP (in case of a serious disease with a short life expectancy) and who were able to complete questionnaires and reach the research centre were invited to participate in the study. The Medical Ethical Committee of the Erasmus Medical Centre Rotterdam approved the study.
First, data from 1688 responders (50%) were collected using a self-administered 113-item questionnaire, which included different questionnaires about symptom frequency and QOL and also addressed marital status, number of children, education level, smoking behaviour, and drinking habits. Second, additional measurements (height, weight, blood pressure, and urinalysis) were performed at the research centre. Finally, in cooperation with the urology department of the Erasmus Medical Centre, the following tests were performed: serum prostate-specific antigen (PSA), digital rectal examination, transrectal ultrasound (TRUS) of the prostate, uroflowmetry, and postvoid residual urine volume. Prostate biopsies were obtained in men suspected of having prostate cancer. Measurements were repeated in three consecutive rounds of follow-up, with an average follow-up of 2.1, 4.2, and 6.5 yr, respectively.
In order not to disturb the natural course of benign prostatic hyperplasia (BPH), no test results, except for PSA values, were given to the participant and his GP.
2.2. Assembly of GP data
A flow chart of the GP data assembly is presented in Fig. 1.
Fig. 1. Assembly of data in general practitioner database.
In the Netherlands, all inhabitants are registered with a GP. When a patient visits any physician during the weekend or at night, his or her own GP is always informed. Data about all visits, contacts, and prescriptions are entered in computerised medical records.
All 16 practising GPs in Krimpen aan den IJssel permitted access to the GP medical records of all participants in the study (n=1688). These records were checked with the N6 computer program (QSR International Pty. Ltd., Melbourne, Australia), which can search and select text files using keywords. Two researchers independently scored whether there was a history of LUTS (before the start of the study) and whether the participant had visited his GP for LUTS and the date of the first visit. When the medical file showed that a person had moved away from the GP's practice (was lost to follow-up) or was deceased, the date of this event was noted. Medical files that showed no hits by N6 were checked manually; none of these files included reports of visits for LUTS.
2.3. Symptoms and measurements
LUTS were assessed using the seven-item International Prostate Symptom Score (IPSS) [9]. The total volume of the prostate and the volume of the transition zone were measured by TRUS. We used the planimetric procedure to determine the most accurate prostate volume [10]. Measurements were performed using a Bruel and Kjaer Medical Falcon Ultrasound Scanner (type 2101) equipped with a 7-MHz biplanar endorectal transducer (type 8808). Postvoid residual urine volume was measured using a transabdominal ultrasound device (Aloka Model SSD-1700 Dyna View, with a 3.5-MHz electronic convex probe), and uroflowmetry (Qmax) was done using a flow meter (Dantec Urodyn 1000, Copenhagen, Denmark).
2.4. Quality of life
To assess generic QOL, we used the short version of the Inventory of Subjective Health (Mini-ISH) and the Sickness Impact Profile (SIP). The Mini-ISH is a 13-item questionnaire on subjective health with a score range of 0–13 [11]. The three domains of the SIP used in this study were emotions (9 items), recreation (8 items), and social interaction (20 items). For each category, a score was computed on the basis of weighing factors for each item, providing scores ranging from 0 to 100 [12].
In contrast to generic QOL questionnaires, disease-specific questionnaires measure QOL on the basis of items closely related to the specific disease and are therefore expected to be more sensitive. To measure the effect of LUTS on QOL, we used the QOL question of the IPSS (IPSS-QOL) and the BII. The IPSS-QOL can be rated on a scale of 0–6 [9]. The BII is a four-question index with a score of 0–13 designed to assess the effect of the symptoms of BPH on health status [13].
For all QOL scales used (disease-specific and generic), a higher score indicates a worse QOL.
2.5. Statistical analyses
To explore the possible effect of different variables on a first GP visit for LUTS within 2 yr after baseline, we performed univariate and multivariate logistic regression analysis. “First GP visit for LUTS” means the first GP visit with complaints of LUTS but without a history of LUTS.
Baseline variables were analysed as continuous variables. A dichotomous variable was constructed for the following because no normal distribution was present in this study population: postresidual volume greater than 50ml, the different SIP domains, having children, living together, current smoking, consuming more than 2 alcoholic drinks of alcohol a day, and educational level. The total domain score was 0 if the SIP domain score was equal to 0 and 1 if the SIP domain score was greater than 0.
Variables with a p value ≤0.25 in the univariate analysis were entered in the multivariate logistic regression analysis [14]. Variables with a p value >0.05 to the effect in the multivariate models were excluded. The data were analysed using SPSS 11.
3. Results
The study cohort consisted of 1688 men. The search program N6 selected 1015 of the files. Review of these files revealed that 182 men had a history of a visit (to a GP or urologist) for LUTS before the start of the study, leaving 1506 men (89%) at risk for visiting their GP with LUTS at a later date. Complete baseline data and GP data were available for these 1506 men. Table 1 shows that men at risk had slightly fewer LUTS and higher QOL than did the total study population. Of the men at risk, 58 (3.9%) visited their GP for LUTS for the first time within 2 yr after baseline.
| |
|
|
 |
|
Total study populationa (N=1688) |
People at riskb (N=1506) |
|
|
Symptoms |
Mean (SD) |
Mean (SD) |
|
|
IPSS |
5.3 (5.4) |
4.8 (4.9) |
|
|
IPSS—irritative |
2.9 (2.7) |
2.7 (2.5) |
|
|
IPSS—obstructive |
2.4 (3.5) |
2.1 (3.1) |
|
|
|
|
|
Quality of Life (QOL) |
Mean (SD) |
Mean (SD) |
|
|
Generic QOL |
|
|
SIP Social |
5.9 (9.6) |
5.6 (9.2) |
|
|
SIP Emotional |
4.0 (9.9) |
3.9 (9.4) |
|
|
SIP Recreation |
10.8 (17.3) |
10.6 (17.4) |
|
|
Mini-ISH |
2.0 (2.3) |
2.0 (2.3) |
|
|
|
|
|
Disease-specific QOL |
|
|
IPSS-QOL |
1.4 (1.2) |
1.2 (1.1) |
|
|
BPH-II |
0.7 (1.4) |
0.6 (1.2) |
|
|
|
|
|
Urologic parameters |
Mean (SD) |
Mean (SD) |
|
|
Prostate volume |
33.7 (14.5) |
33.6 (14.2) |
|
|
Transition zone volume |
16.2 (12.3) |
16.0 (11.9) |
|
|
Maximum urinary flow rate |
11.5 (6.9) |
11.6 (6.9) |
|
|
Residual volume |
21.8 (50.5) |
21.7 (51.5) |
|
|
|
|
|
Age (yr) |
Percentage |
Percentage |
|
|
50–54 |
20.3 |
21.4 |
|
|
55–59 |
25.4 |
25.7 |
|
|
60–64 |
24.0 |
23.5 |
|
|
65–69 |
19.3 |
19.0 |
|
|
70–74 |
7.9 |
7.4 |
|
|
75+ |
3.1 |
2.9 |
|
|
|
|
|
Under treatment for |
Percentage |
Percentage |
|
|
Diabetes mellitus |
3.4 |
3.5 |
|
|
Hypertension |
15.9 |
15.8 |
|
|
COPD |
4.5 |
4.4 |
|
|
Parkinson's disease |
0.1 |
0.1 |
|
|
Cardiac disease |
6.2 |
6.1 |
|
|
Chronic urinary tract infection |
0.8 |
0.5 |
|
|
Liver disease |
0.4 |
0.4 |
|
|
One or more of the above |
24.8 |
24.5 |
|
| |
|
|
a 1688 responders at baseline.
b Men without a history of LUTS and at risk for visiting their GP for LUTS after the start of the study.
Table 2 shows the results of logistic regression analysis of determinants predicting a GP visit for LUTS. In the univariate analysis, determinants significantly associated with a first GP visit for LUTS were postvoid residual volume, Qmax, prostate volume, age, symptom severity, disease-specific QOL (IPSS-QOL and BII), and social and emotional generic QOL (p≤0.05). Both irritative IPSS and obstructive IPSS were related to a first GP visit for LUTS. The multivariate model with only urologic determinants (prostate volume, postvoid residual volume, and maximum flow rate) gave a proportion of explained variance (R2) of 10%. When symptom severity (IPSS) and QOL (disease-specific and generic) were added to the model with only urologic variables, IPSS, prostate volume, postvoid residual volume, and SIP (social) remained significant determinants of a first GP visit for LUTS (R2=22%).
| |
|
|
|
Determinants |
OR |
95% CI |
p value |
|
|
Univariate analysis |
|
|
IPSSa |
1.13 |
1.09–1.18 |
<0.001 |
|
|
IPSS—irritativea |
1.29 |
1.19–1.39 |
<0.001 |
|
|
IPSS—obstructivea |
1.17 |
1.10–1.23 |
<0.001 |
|
|
Agea |
1.09 |
1.05–1.13 |
<0.001 |
|
|
Postvoid residual urine volume >50mlb |
3.22 |
1.73–5.99 |
<0.001 |
|
|
Prostate volumea |
1.04 |
1.03–1.05 |
<0.001 |
|
|
Transition zone volumea |
1.04 |
1.03–1.06 |
<0.001 |
|
|
Transition zone indexa |
1.06 |
1.04–1.08 |
<0.001 |
|
|
Maximum urinary flow ratea |
0.93 |
0.88–0.98 |
0.006 |
|
|
Mini-ISHa |
1.07 |
0.96–1.19 |
0.225 |
|
|
IPSS-QOLa |
1.88 |
1.49–2.36 |
<0.001 |
|
|
BPH-IIa |
1.48 |
1.30–1.69 |
<0.001 |
|
|
Socially impairedb |
4.48 |
2.18–9.22 |
<0.001 |
|
|
Emotionally impairedb |
1.97 |
1.12–3.46 |
0.019 |
|
|
Recreationally impairedb |
1.89 |
1.10–3.26 |
0.021 |
|
|
Living togetherb |
0.58 |
0.14–2.42 |
0.456 |
|
|
Childrenb |
1.11 |
0.43–2.82 |
0.832 |
|
|
Smokingb |
1.23 |
0.68–2.22 |
0.499 |
|
|
<2 units of alcohol a dayb |
0.62 |
0.28–1.38 |
0.237 |
|
|
Education levelb |
1.37 |
0.66–2.85 |
0.398 |
|
|
|
|
|
Final multivariate model with determinantsc with p≤0.05, R2=0.22 |
|
|
IPSSa |
1.14 |
1.08–1.19 |
<0.001 |
|
|
Prostate volumea |
1.03 |
1.02–1.05 |
<0.001 |
|
|
Postvoid residual urine volume >50mlb |
2.57 |
1.24–5.32 |
0.011 |
|
|
SIP—social scoreb |
3.91 |
1.76–8.66 |
<0.001 |
|
| |
|
|
a Continuous variable.
b Dichotomous variable.
c Only variables with a significance of p<0.25 in univariate analysis were used for the multivariate model.
Using the variable transition zone index instead of prostate volume in the model, the transition zone index was significant (p=0.05) but less significant than the prostate volume (p=0.02) and did result in a higher explained variance in GP visit for LUTS.
4. Discussion
Our study demonstrates that prostate volume, postvoid residual volume, IPSS, and social generic QOL are important determinants of first GP consultation in men with LUTS. Urologic measurements and self-reported items contribute almost equally to first GP consultation for LUTS.
In the Krimpen study, 50% of the invited men responded. The mean symptom and QOL scores of the responders indicate mildly severe LUTS and a reasonably good QOL. A questionnaire was sent to those who did not participate at baseline, to investigate the characteristics of this group. Given that the prevalence of IPSS less than 7 was lower among nonparticipants [8], we conclude that the prevalence and incidence of a first GP visit for LUTS in fact must be slightly lower than measured in the present study. However, because this study reports on the relationship between determinants and GP consultation, this bias did not influence our results. Our results are also not biased by knowledge of test results before the GP visit. Participants and their GPs were not exposed to this information. Only the PSA value was given to the GP, because of the need to detect prostate cancer. In the present study, possible fear of prostate cancer most probably did not play a role in GP consultation for LUTS, because men with prostate cancer were filtered out of the study population. In this type of epidemiologic research, the reliability of electronic medical records is a problem because information entered by the physician is often variable. However, because of the large number of keywords (82) used in the search, our concerns about missing hits are minimal.
Although the odds ratios (ORs) of the IPSS and prostate volume are just above 1, they are not only statistically significant but also clinically significant. These variables are continuous variables, which means that, for example, with an increase of 4 points in IPSS, the change associated with a first GP visit for LUTS is +4.56 (4*1.14).
Like others [15], [16], we found that maximum flow rate and age were univariately significantly associated with first GP visit for LUTS. We could not confirm the finding of Wolfs et al. [15] that being a current smoker was a determinant of a GP visit for LUTS. Previous studies [17], [18] concluded that increased symptom severity, poor Qmax, and a high postvoid residual urine volume are major risk factors for overall clinical progression of LUTS/BPH. These determinants, except Qmax, are the same factors predicting a GP visit for LUTS in our study. The univariate significant relationship between Qmax and a first GP visit for LUTS disappeared after we adjusted for other determinants in the multivariate analyses. In addition, we conclude that social generic QOL is an important factor in presenting LUTS to a GP.
An important underlying cause of LUTS, BPH seems to be explained mainly by the growth of the transition zone of the prostate [19]. In our study, a greater transition zone volume gave an almost equal OR (1.036; 95% confidence interval [CI], 1.03–1.06) compared with total prostate volume (OR, 1.035; 95% CI, 1.03–1.05) but did not increase the variance of the model (–0.3 %). However, because our outcome measure was the seeking of primary care rather than, for example, acute urinary retention or need for surgery, this finding is not remarkable.
The explained variance (22%) of this model predicting a GP visit for LUTS is somewhat low. The variance could have been limited because of variation over time in health status or symptoms of the participants. We conclude that there might be other determinants of a GP visit for LUTS. This is consistent with the finding of Norby et al. [20] that factors other than symptom severity must influence health care-seeking behaviour; in their study, less than 50% of men and women with severe LUTS had seen a physician within 2 yr. Previous results of the Krimpen study [unpubl. data, E.T. Kok, F.P.M.J. Groeneveld, J.J.V. Busschbach, J.L.H.R. Bosch, S. Thomas, A.M. Bohnen] demonstrate the effect of various coping styles on QOL in men with LUTS; thus, personal traits, such as coping behaviour, may play a role. Further research is needed to explore this assumption.
5. Conclusions
We conclude that the number of men in the community first visiting a GP for LUTS in 2 yr is still limited to a small percentage. Almost a quarter of first GP visits for LUTS in men can be predicted by prostate volume, postvoid residual urine volume, IPSS, and social generic QOL. Both urologic measurements and self-reported information about symptoms and QOL can help to select those who will benefit most from medical care and help to reassure those men not likely to need help in the near future.
Acknowledgements
The Krimpen study was financially supported by the Foundation for Urologic Research Rotterdam (SUWO), GlaxoSmithKline, and Pfizer.
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Esther T. Koka, Frans P.M.J. Groenevelda, Jochem Gouweloosa, Rikkert Jonkheijma, J.L.H. Ruud Boschb, Siep Thomasa, Arthur M. Bohnena
a Department of General Practice, Erasmus Medical Centre, Rotterdam, The Netherlands
b Department of Urology, University Medical Center Utrecht, Utrecht, The Netherlands
Accepted 9 March 2006 published online 31 March 2006.Please log-in or register in order to submit comments. Powered by AkoComment! |
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