Search tips
Search criteria 


Logo of jcoHomeThis ArticleSearchSubmitASCO JCO Homepage
J Clin Oncol. 2009 May 1; 27(13): 2144–2150.
Published online 2009 March 23. doi:  10.1200/JCO.2008.16.1901
PMCID: PMC2738633

Prospective Study of Factors Predicting Adherence to Medical Advice in Men With Testicular Cancer



To identify predictive factors of adherence to medical advice, specifically the likelihood of attendance to a recommended follow-up regimen in patients with newly diagnosed testicular cancer.

Patients and Methods

This was a prospective study measuring initially not only aspects of the doctor–patient interview, but also a range of demographic, psychological, social, and medical factors, and then recording attendance behavior on follow-up. All 209 new patients with testicular cancer referred between June 1992 and May 1995 were approached, and 184 men consented and completed questionnaires. The nonadherence end point (nonattender) was two failures to attend an outpatient appointment at least 1 month apart, despite a written reminder.


Thirty-two participants (17%) were classified as nonattenders. No significant differences were found between attenders and nonattenders in the majority of psychosocial and medical variables that might have predicted nonadherence to medical advice. There was a highly significant association between nonattendance and a patient's perception of an unsatisfactory affective relationship with his clinician (P = .005; hazard ratio, 3.1; 95% CI, 1.4 to 6.6).


Patients who perceived an unsatisfactory affective relationship with their clinician that included an inability to trust the clinician and a perception that they were not being treated as “a person” were subsequently more likely to disregard medical advice regarding follow-up. Attention to the ways young men may wish to communicate with their clinicians is important, bearing in mind that they may not necessarily adhere to stereotypical images of masculine self-dependence.


The extent to which patients adhere to medical advice varies in a range of different illnesses, including cancer.19 This may have a considerable effect on outcomes in some management protocols such that the likelihood of adherence could be a factor influencing the optimal treatment recommendation. An example of this is the policy of surveillance after orchiectomy for clinical stage I testicular germ cell cancers. The rationale is to defer treatment until those with micrometastases have demonstrated the need for chemotherapy by developing overt clinical recurrence. Overall the recurrence rate in nonseminoma is approximately 30%, and in those patients who experience recurrence, it can usually be detected while the metastases are small and relatively easy to cure.10,11 Surveillance is required also for patients with low-stage nonseminoma managed by retroperitoneal lymph node dissection, although the recurrence rate is much lower at approximately 10%.12 In metastatic nonseminoma, the cure rate and the amount of treatment needed relates to the volume of metastatic disease.13,14 Patients with stage I disease who do not attend follow-up assessments have a high risk of more advanced recurrence. If nonattendance was predictable, these patients could be advised of the alternative policy of immediate adjuvant chemotherapy.15,16 Similarly, detection of recurrence after treatment for metastatic disease may be associated with a better prognosis if the tumor burden is low.16a

Nonadherence to medical advice relates to a range of possible factors, including health beliefs,6,17 education regarding medical management,18,19 underemployment,19 limited understanding of illness,19 social class,20 patient dissatisfaction,21 anxiety,22,23 highly committed religious beliefs,22 and attitude to self-responsibility for health.24 There may be opportunity to respond to these if initial clinical interactions are empathetic and supportive.18,25 Thus it is particularly important for health care professionals to understand whether their initial interaction with a patient may influence adherence to advice, and a measure of this interaction that has not been evaluated in this context is the Medical Interview Satisfaction Scale (MISS).26 We undertook a prospective study of adherence to medical advice concerning attendance to a testicular cancer follow-up clinic by assessing through self-reported questionnaires not only initial clinical interactions, but also other psychological and social factors that might predict likelihood of nonattendance. Attendance behavior was derived from hospital records.


Setting and Participants

The study involved new patients with testicular tumor aged 18 years and older seen at the Royal Marsden Hospital, Sutton, United Kingdom, between 1992 and 1995. Attendance behavior up to 2002 was analyzed, and the median follow-up was 7 years. Men who had been informed of their diagnosis but who had not yet had their treatment regimen confirmed were approached within 8 weeks after orchiectomy and approximately 2 weeks postreferral (median time from diagnosis to enrollment was 5 weeks). Ineligibility included intellectual impairment, bilateral germ cell tumors, disease relapse, non–United Kingdom residency, and extragonadal primary disease presentation.


The study design required initial completion of self-reported questionnaires to score a range of psychosocial factors followed by analysis of subsequent attendance behavior for the end point of nonadherence to medical advice. Individual consent was required to complete the questionnaires, and potential participants were approached before recommendation of a treatment plan. The patient information sheet explained that research would “help us understand the perceptions and responses of patients who have recently had a diagnosis of testicular cancer.” To avoid confounding the study, the end point of recorded outpatient attendance was not made explicit. The protocol was approved by the Royal Marsden Hospital Local Research Ethics Committee.

Patients with stage I nonseminoma managed by surveillance were assessed for attendance from the time of their first follow-up appointment. Patients undergoing chemotherapy or radiotherapy were monitored from first follow-up appointment after treatment. Follow-up constituted blood tests for tumor markers, chest radiographs, and a clinical examination. If a patient failed to attend a scheduled visit, he was sent a reminder to attend within 1 month after the failed visit. Men with two failed appointments at least 1 month apart, despite a written reminder, were classified as nonattenders. Follow-up information was obtained on all nonattenders either by direct contact or through their primary care physician. Patients who transferred care to other hospitals would be censored but not necessarily defined as a nonattender.

Statistical Methods

Attendance to medical advice was measured by follow-up attendance records. The probability of nonattendance or an event was calculated using Kaplan and Meier methods measured from the date of the first follow-up appointment. Factors were then compared by univariate and multivariate analysis using the Cox proportional hazards model. Hazard ratios (HRs) and their 95% CIs were calculated from the Cox proportional hazards model. Uncorrected P values less than .05 were considered statistically significant. Factor scores were dichotomized above and below the median value. The analysis was repeated in four different ways: dichotomizing at the lower quartile, dichotomizing at the upper quartile, using the actual scores as continuous variables, and dividing the data into four groups at the quartile. These were done to investigate the effect of the cutoff points on the significance of a particular factor. A total of 206 patients were estimated to be needed to demonstrate a 20% difference in attendance at two different levels of a variable (70% to 90%) based on α = 5% and power of 90%.


The MISS26 investigates ways in which patients perceive interaction with their attending clinician. This 26-item scale (Cronbach α coefficient = 0.93) consists of a cognitive and affective subscale (nine items each) and a behavioral subscale (eight items), with high scores denoting a positive response (Cronbach α coefficients were calculated to be 0.87, 0.86, and 0.87 respectively). Cognitive items refer to the doctor's giving explanations and information and the patient's self-perceived understanding of diagnosis, etiology, prognosis, and effects of treatment. Affective items refer to the patient's perception of the relationship he/she has with the doctor. Behavioral items measure evaluation of the physician's professional behavior, physical examination, diagnostic procedures, treatments, and dispensation of advice. Sensitivity was obtained by correlating subscale scores with indices of verbal interaction obtained by independently coded interviews between patients (including young men) and their clinicians.26 For example, affective satisfaction was significantly correlated with exchanges that consisted mainly of patients telling their “story” in their own words as opposed to answering closed questions and physicians acknowledgment of patients' accounts and concerns.26

The Cancer-Related Anxiety and Helplessness Scale27 is a 12-item self-report measure of cancer anxiety and a “nothing more to be done” attitude. A lower score denotes greater anxiety/helplessness. The State/Trait Personality Inventory (20-item version)28 measures innate and transient anxiety and consists of 10 items on each. The Course of Illness subscale of the Cancer Locus of Control Scale29 is a self-administered questionnaire designed to measure the extent to which individuals perceive internal control over factors relating to the cause and course of illness. In this study, only the course of illness subscale was used. A high score is indicative of strong internal control. The Mental Adjustment to Cancer scale30 shows the ways in which patients cope with their diagnosis, measuring “Fighting Spirit,” “Helplessness and Hopelessness,” “Anxious Preoccupation,” “Fatalism,” and “Avoidance.” The Health Belief Model31 (HBM), used in previous studies,6 investigates whether the behavior of patients is significantly affected by certain beliefs such as concern about health, health motivation, perceived susceptibility to the illness/relapse, perceived seriousness of the disease, and a belief that benefits outweigh costs. High scores denote the seriousness of the disease, perceived susceptibility to the disease, and relapse. Low scores denote susceptibility, including likely relapse once diagnosed. Health motivation, including intention to attend follow-up, is assessed in four items, with high scores denoting negative motivation and intention; perceived benefits are assessed in seven items, with low scores denoting the benefits of hospital visits. One of those items (“Why do you think you are asked to come to this hospital?”) included six scales ranging from 6 (“It will not help at all”) to 1 (“The cancer can be cured”). Assessment of “Barriers” (nine items) included efficacy of medical input and social disruption, with high scores denoting difficulty. Social class and other possible mediating variables were recorded, including home support and employment (Table 1).

Table 1.
Demographic, Social, and Medical Characteristics of Patients (N = 184)


A total of 209 eligible men attended the unit during the recruitment period. Twenty-five men were excluded: 13 men failed to complete questionnaires after giving consent, three men refused outright, and nine men were missed and were not asked to participate. One hundred eighty-four men consented and completed questionnaires. There were no clear demographic or medical differences between those who did or did not participate. One participant with metastases died, and seven men experienced relapse within the study period. There was no relationship between attendance and relapse. All consenting patients who completed questionnaires were monitored for attendance adherence. One attending patient transferred his care as a result of social circumstances and was censored but was not considered to be a nonattender.

Table 1 shows the demographic and medical factors that characterized attenders and nonattenders. There were no differences in attendance behavior between the subgroups, including treatment received, although closer adherence to medical advice in older men was evident (HR = 0.96; 95% CI, 0.92 to 0.99; P = .045). After a median follow-up period of 7.7 years, 32 men were classified as nonattenders. The 5-year probability of remaining an attender was 86.3% (95% CI, 80.0% to 90.7%). A total of 62.5% of events occurred in the first 3 years of the study. By 8 years, the rate was 80% (95% CI, 72.7% to 85.6%). With 32 nonattenders, the study had 80% power to detect HRs of 2.6 or above.

Using a univariate analysis, there were no significant differences in the attendance behavior of those scoring above or below the median for the majority of psychosocial assessment (Table 2). Scores were in general unremarkable, with relatively few upper or lower extremes. Men's perceived susceptibility to testicular cancer and likelihood of relapse and/or worsening of disease, as assessed in the HBM questionnaire, showed a relatively low median score of 6 (range, 3 to 12). The difference between groups reached a P of .078 indicating a trend toward attenders feeling more vulnerable. Possible mediating variables, such as home support, employment, religious practice, and knowing other patients with testicular cancer, did not impact significantly on behavior.

Table 2.
Cox Regression Analysis of Psychosocial Measures

There was a highly significant association between nonattendance and men's perception of an unsatisfactory affective relationship with their clinician as measured on the MISS26 scale (Fig 1). The affective relationship remained the only significant factor when the analysis was repeated using either a continuous scale or other cutoff points than the median score, although when the data was dichotomized at the upper quartile, none of the factors were significant. In the MISS affective scale, the HR for risk of nonattendance was not higher in the uppermost compared with the third quartile. When the scales were analyzed as continuous variables, the affective MISS scale was again the only significant factor (P < .02); no other factors reached a P value of less than .1. Men with lower scores than the median (< 38) were 3.1 times more at risk of nonattendance (95% CI, 1.4 to 6.6) than those with higher scores (P = .005). By 8 years, men who were scoring low overall on the Affective Scale maintained only 70% (95% CI, 57.4% to 70.3%) rate of attendance compared with those scoring high overall (≥ 38) who maintained an 89% (95% CI, 79.6% to 94.1%) rate. On multivariate analysis, only the MISS Affective Scale remained significant (P = .003), with an HR of 3.06 (95% CI, 1.42 to 6.63; age, P = .067; stage, P = .625; histology, P = .722; socioeconomic status, P = .401; and educational level, P = .625).

Fig 1.
Probability of nonattendance analyzed by response on the Medical Interview Satisfaction Scale Affective Scale, grouped as either above (n = 95) or below (n = 88) the median score of 38.

The items comprising the Affective Scale of the MISS were then analyzed individually, and four were significant on univariate Cox regression analysis. These were item 11 (“I really feel understood by the doctors”; P = .019), item 15 (“I feel the doctors accept me as a person”; P = .003), item 16 (“ I feel the doctors haven't taken my problems seriously”; P = .048), and item 18 (“The doctors are people I would trust with my life”; P = .001). On multivariate analysis, only items 15 (P = .001) and 18 (P ≤ .001) remained significant (Table 3). Age was not included in this analysis because it was not significant in the overall multivariate analysis. Men who were unsure about whether the attending doctor was accepting them “as a person” or whether they would “trust their lives” to him/her were less likely to adhere to follow-up advice.

Table 3.
Perceived Affective Behavior of Clinicians at Time of Diagnosis: Significant Items on Multivariate Cox Regression Analysis of the Medical Interview Satisfaction Scale


This study identified an association between attendance behavior and an affective relationship between patients with testicular cancer and their clinicians as measured by the MISS scale.26 Nonattenders were ambivalent regarding the trust they had in their clinicians and were more likely to feel that they had not been accepted “as a person.” Two other items in the MISS affective scale were only significant on univariate analysis, namely, that the patient “felt understood” and that their problems had been “taken seriously.” The high association between items in this scale (Cronbach's α = 0.86) implies that these lost significance on multivariate analysis because of overlap and that all four factors were likely to be relevant. Analysis of the MISS scale by quartile scores suggested that it was more important to avoid a score below the median than to seek a very high score. We found no association between attendance behavior and other possible predictive variables, including social, psychological, medical, and demographic factors, although on univariate analysis, older patients were more likely to be attenders. It may be that mature men respond to the threat of serious disease.19

Our data do not provide in-depth understanding of the perceived meaning of the terms used in the affective component of the MISS26 scale. Trust in doctors is said to be built on a need for “interpersonal competence involving caring, concern, and compassion, with listening as a central focus,”32 whereas “acceptance as a person” may allude to clinicians' respect for the patient's idiosyncratic characteristics.33 The high internal consistency of the affective subscale indicates reliability of the items in question.26

Men who are affected by issues such as caring and compassion are exceptions to the stereotype of the stoic male patient with cancer and his need to “go it alone” when facing disease.33,34 This attitude may, however, play a part in how men access health provision.35,36 Young patients with testicular cancer are known to hide vulnerability and despise pity,33 although some may wish to relinquish that “masculine” facade when ill.33 We did not specifically investigate aspects of masculinity that may impact behavior. Self-report measures of masculinity are intrinsically biased.37 More research using qualitative methodologies may clarify these factors in young men who are experiencing serious illness, as well as answering important questions, such as whether and why some young men find it difficult to admit to regular hospital care.

Our study differs from a Canadian study6 that investigated compliance to follow-up in patients with testicular cancer but had methodologic weaknesses. In that study, patients were observed retrospectively for “over a year” only. Twenty-five men were “chart reviewed” for follow-up behavior; 27 men (14 who underwent chemotherapy and 11 who underwent orchiectomy) completed questionnaires that relied on items pertaining to the HBM.31 Patients undergoing chemotherapy perceived their disease as “extremely dangerous” and follow-up as being more beneficial as compared with patients who had undergone surgery only. In view of the small sample size, this treatment-related difference may have been due to patient selection. Because the study was retrospective, bias may have been introduced as perceptions of disease could be affected by the outcomes of treatment. Moreover, studies using the HBM have shown differing results.38 Our prospective study recognized this and addressed additional factors to HBM items that may impinge on adherence to follow-up. In addition, cultural factors may underlie the differences between the two studies, including the ways in which clinicians in the United Kingdom and United States impart information and patients receive it.39

There are a number of caveats with regard to interpretation of our study. Although we identified the Affective subscale of the MISS as a predictor of nonattendance, the rather small number of such events31 would reduce power of the study to exclude a moderate impact of other factors. We have no knowledge as to what was actually said by clinicians to their patients or whether those clinicians were junior doctors, surgeons, or medical oncologists. Nonattendance may have been caused by life events, such as bereavement or job loss, occurring within the study period. However, although this study deployed a strict definition of nonadherence to medical advice, it also gave a generous leeway to men before they were classified as nonattenders. Our results simply highlight the ways in which patients' perceptions of aspects of their affective relationship with the doctor might be associated with adherence to advice about attendance in one cancer type and in a young age group of men. We suggest that clinicians need to establish a relationship with patients that is individual and generates trust and mutual respect.

Our study has some limitations. This study was based on young adult men with testicular cancer in a single southwest London hospital where it was impossible to access robust representation of non-Caucasian groups.

In conclusion, patients who perceived an unsatisfactory affective relationship with their clinician that included an inability to trust the clinician and a perception that they were not being treated as a person were subsequently more likely to disregard medical advice regarding follow-up. Improved communication that embraces the needs of patients with testicular cancer to establish a satisfactory doctor–patient relationship may lead to improved adherence to medical advice.


We thank all patients who took part in the study.


Supported in part by the National Health Service Executive; NHS funding to the NIHR Biomedical Research Center; the Institute of Cancer Research; and Grant No. C46/A2131 from the Bob Champion Cancer Trust and Cancer Research UK Section of Radiotherapy.

The views expressed in this publication are those of the authors and not necessarily those of the National Health Service Executive.

Authors' disclosures of potential conflicts of interest and author contributions are found at the end of this article.


The author(s) indicated no potential conflicts of interest.


Conception and design: Clare Moynihan, Alan Horwich

Administrative support: Louise Burchell

Provision of study materials or patients: Robert Huddart, David P. Dearnaley, Alan Horwich

Collection and assembly of data: Louise Burchell

Data analysis and interpretation: Clare Moynihan, Andy R. Norman, Yolanda Barbachano, Alan Horwich

Manuscript writing: Clare Moynihan, Alan Horwich

Final approval of manuscript: Clare Moynihan, Andy R. Norman, Yolanda Barbachano, Louise Burchell, Robert Huddart, David P. Dearnaley, Alan Horwich


1. Cramer J, Spilker J. Patient Compliance in Medical Practice and Clinical Trials. New York, NY: Raven Press; 1993.
2. Cramer J, Mattson R. Monitoring Compliance and Anti-epileptic Drug Therapy. New York, NY: Raven Press; 1993.
3. West KM. Diet therapy of diabetes: An analysis of failure. Ann Intern Med. 1973;79:425–434. [PubMed]
4. Spilker B. Methods of Assessing and Improving Patient Compliance in Clinical Trials. New York, NY: Raven Press; 1993.
5. Moul J. Refusal of cancer treatment in testicular cancer patients. J Nat Cancer Institute. 1989;81:1587–1588. [PubMed]
6. Young BJ, Bultz BD, Russell JA, et al. Compliance with follow-up of patients treated for non-seminomatous testicular cancer. Br J Cancer. 1991;64:606–608. [PMC free article] [PubMed]
7. Morrissey PE, Flynn ML, Lin S. Medication noncompliance and its implications in transplant recipients. Drugs. 2007;67:1463–1481. [PubMed]
8. Winnick S, Lucas D, Hartman A, et al. How do you improve compliance? Pediatrics. 2005;115:e718–e724. [PubMed]
9. Partridge AH, Avorn J, Wang PS, et al. Adherence to therapy with oral anti-neoplastic agents. J Natl Cancer Inst. 2002;94:652–662. [PubMed]
10. Read G, Stenning SP, Cullen MH, et al. Medical Research Council prospective study of surveillance for stage I testicular teratoma: Medical Research Council Testicular Tumors Working Party. J Clin Oncol. 1992;10:1762–1768. [PubMed]
11. Sharir S, Jewett MA, Sturgeon JF, et al. Progression detection of stage I nonseminomatous testis cancer on surveillance: Implications for the followup protocol. J Urol. 1999;161:472–475. discussion 475-476. [PubMed]
12. Stephenson AJ, Bosl GJ, Bajorin DF, et al. Retroperitoneal lymph node dissection in patients with low stage testicular cancer with embryonal carcinoma predominance and/or lymphovascular invasion. J Urol. 2005;174:557–560. [PubMed]
13. International Germ Cell Consensus Classification: International Germ Cell Consensus Classification: A prognostic factor-based staging system for metastatic germ cell cancers. J Clin Oncol. 1997;15:594–603. [PubMed]
14. Horwich A, Shipley J, Huddart R. Testicular germ-cell tumours. Lancet. 2006;367:754–765. [PubMed]
15. Cullen MH, Billingham LJ, Cook J, et al. Management preferences in stage I non-seminomatous germ cell tumours of the testis: An investigation among patients, controls and oncologists. Br J Cancer. 1996;74:1487–1491. [PMC free article] [PubMed]
16. Dearnaley DP, Fossa SD, Kaye SB, et al. Adjuvant bleomycin, vincristine and cisplatin (BOP) for high-risk stage I non-seminomatous germ cell tumours: A prospective trial (MRC TE17) Br J Cancer. 2005;92:2107–2113. [PMC free article] [PubMed]
16a. Beyer J, Rick O, Siegert W, et al. Salvage chemotherapy in relapsed germ cell tumors. World J Urol. 2001;19:90–93. [PubMed]
17. Calnan M, Rutter DR. Do health beliefs predict health behaviour? A follow-up analysis of breast self-examination. Soc Sci Med. 1988;26:463–465. [PubMed]
18. Cromer B. Behavioural Strategies to Increase Compliance in adolescents. In: Cramer J, Spilker B, editors. Patient Compliance in Medical Practice and Clinical Trials. New York, NY: Raven Press; 1993. pp. 99–105.
19. Moul JW. Refusal in testicular cancer patients: Implications for surveillance. Br J Cancer. 1992;65:786. [PMC free article] [PubMed]
20. Lebovits AH, Strain JJ, Schleifer SJ, et al. Patient non-compliance with self-administered chemotherapy. Cancer. 1990;65:17–22. [PubMed]
21. Fitzpatrick R. In The Experience of Illness. London: Tavistock; 1984. pp. 153–175.
22. Blotcky AD, Cohen DG, Conatser C, et al. Psychological characteristics of adolescents who refuse cancer treatment. J Consulting and Clin Psych. 1985;53:729–731. [PubMed]
23. Taylor HG, Brown AW, Jr, Butler WM, et al. Treatment experience with nonseminomatous testicular cancer in patients with stage II and stage III disease. Cancer. 1981;48:1110–1115. [PubMed]
24. Wallaston K, Wallaston B. Who is responsible for your health: The construct of health locus of control. In: Sanders G, Suls J, editors. Social Psychology of Health and Illness. Hillsdale, NJ: Erlbaum; 1982. pp. 160–170.
25. Bultman D, Svarstad B. Effects of physician communication style on medication beliefs and adherence with antidepressant treatment. Patient Educ Couns. 2000;40:173–185. [PubMed]
26. Wolf MH, Putnam SM, James SA, et al. The Medical Interview Satisfaction Scale: Development of a scale to measure patient perceptions of physician behavior. J Behav Med. 1978;1:391–401. [PubMed]
27. Kash K, Holland J, Halper M. Women at high risk for breast cancer: A surveillance programme. J Natl Cancer Inst. 1992;84:24–30. [PubMed]
28. Spielberger C. Preliminary Test Manual for the State-Trait Personality Inventory. Tampa, FL: Center for Research in Behavioral Medicine and Health Psychology, University of South Florida; 1990.
29. Watson M, Pruyn J, Greer S, et al. Locus of control and adjustment to cancer. Psychol Rep. 1990;66:39–48. [PubMed]
30. Watson M, Greer S, Young J, et al. Development of a questionnaire measure of adjustment to cancer: The MAC scale. Psychol Med. 1988;18:203–209. [PubMed]
31. Janz NK, Becker MH. The Health Belief Model: A decade later. Health Educ Q. 1984;11:1–47. [PubMed]
32. Mechanic D, Meyer S. Concepts of trust among patients with serious illness. Soc Sci Med. 2000;51:657–668. [PubMed]
33. Moynihan C. Theories in health care and research: Theories of masculinity. BMJ. 1998;317:1072–1075. [PMC free article] [PubMed]
34. Nicholas DR. Men, masculinity, and cancer: Risk-factor behaviors, early detection, and psychosocial adaptation. J Am Coll Health. 2000;49:27–33. [PubMed]
35. Courtenay WH. Constructions of masculinity and their influence on men's well-being: A theory of gender and health. Soc Sci Med. 2000;50:1385–1401. [PubMed]
36. Banks I. No man's land: Men, illness, and the NHS. BMJ. 2001;323:1058–1060. [PMC free article] [PubMed]
37. Clatterbaugh K. What is problematic about masculinities? Men Masculinities. 1998;1:24–45.
38. Harrison JA, Mullen PD, Green LW. A meta-analysis of studies of the Health Belief Model with adults. Health Educ Res. 1992;7:107–116. [PubMed]
39. Cramer J. Overview of methods to measure and enhance patient compliance. In: Cramer J, Spilker B, editors. Patient Compliance in Medical Practice and Clinical Trials. New York, NY: Raven Press; 1993. pp. 3–10.

Articles from Journal of Clinical Oncology are provided here courtesy of American Society of Clinical Oncology