Outpatient-Shopping Behavior and Survival Rates in Newly Diagnosed Cancer Patients

Published Online: September 19, 2012
Shang-Jyh Chiou, DrPH; Shiow-Ing Wang, PhD; Chien-Hsiang Liu, PhD; and Chih-Liang Yaung, PhD
Objectives: To evaluate the appropriateness of the definition of outpatient-shopping behavior in Taiwanese patients.

Study Design: Linked study of 3 databases (Taiwan Cancer Registry, National Health Insurance [NHI] claim database, and death registry database).

Methods: Outpatient shopping behavior was defined as making at least 4 or 5 physician visits to confirm a cancer diagnosis. We analyzed patient-related factors and the 5-year overall survival rate of the outpatient-shopping group compared with a nonshopping group. Using the household registration database and NHI database, we determined the proportion of outpatient shopping, characteristics of patients who did and did not shop for outpatient therapy, time between diagnosis and start of regular treatment, and medical service utilization in the shopping versus the nonshopping group.

Results: Patients with higher incomes were significantly more likely to shop for outpatient care. Patients with higher comorbidity scores were 1.4 times more likely to shop for outpatient care than patients with lower scores. Patients diagnosed with more advanced cancer were more likely to shop than those who were not. Patients might be more trusting of cancer diagnoses given at higher-level hospitals. The nonshopping groups had a longer duration of survival over 5 years.

Conclusions: Health authorities should consider charging additional fees after a specific outpatient- shopping threshold is reached to reduce this behavior. The government may need to reassess the function of the medical sources network by shrinking it from the original 4 levels to 2 levels, or by enhancing the referral function among different hospital levels.

(Am J Manag Care. 2012;18(9):488-496)
Understanding the factors that influence patients to shop for outpatient care after a cancer diagnosis can aid in determining whether the definition of outpatient-shopping behavior is appropriate.

  • Patients with higher individual incomes and higher comorbidity scores were more likely to shop for outpatient care.

  • Patients with more advanced cancer tended to shop more frequently for outpatient care.

  • Patients may be more trusting of cancer diagnoses given at higher-level hospitals.
With increasing life expectancy and an aging population, the focus of healthcare in Taiwan has changed from acute infectious diseases to chronic diseases such as diabetes, hypertension, and cancer. Since 1992, the incidence of cancer has increased annually. Additionally, cancer has become one of the leading causes of death,1 accounting for nearly one-third of all deaths in Taiwan, according to an annual report by the Department of Health. Cancer is not a single disease, and a number of mysteries regarding its etiology remain.

For patients, cancer is a life-threatening disease with no cure. However, modern medicine can enhance patients’ quality of life so long as patients follow the clinical protocol. Most patients can obtain a good quality of life, and survival rates are promising.2 However, patients’ behavior has a major influence on their survival rate. Generally, early diagnosis and treatment are fundamental. Therefore, understanding the relevant factors in patients’ healthcare-seeking behavior can improve the subsequent treatment and prognosis.

Few studies have systematically investigated patients’ psychological conditions to determine the factors influencing their healthcare-seeking behavior.3 Patients, particularly those diagnosed with cancer, might want additional medical opinions (also known as doctor-shopping behavior) because of their perceptions of laboratory testing errors, incorrect diagnoses, or misunderstandings.4-6 Thus, greater attention must be paid to patient behavior to develop useful support strategies, particularly for cancer patients. Most studies have found a relationship between patients’ healthcareseeking behavior and utilization of medical services.7,8 Appropriate behaviors can reduce waste and benefit society. By contrast, according to economic theory, a number of negative events (eg, moral failures) can result in excessive usage, especially of the national health insurance system, and are associated with shopping behavior. The various healthcare delivery systems in different countries have focused on different issues associated with doctor-shopping behavior.9,10 In Taiwan, after the National Health Insurance (NHI) program was launched, some studies found that shopping behavior frequently occurred under this system because of the lack of restrictions, low costs, and reduction of barriers to access.11 Most importantly, shopping behavior can increase medical expenses, reduce the quality of continuous care, and cause waste.12,13 These unfavorable outcomes burden the already fragile healthcare financial system.

Patient and healthcare provider characteristics, as well as the scope of medical resources, all influence doctor-shopping behavior.14 A number of studies found that people with low socioeconomic status do not benefit from cancer prevention therapies as much as people in higher socioeconomic status groups.15,16 To date, few studies have systematically explored the relationship between the survival rates and shopping behaviors of cancer patients.17,18

Another complication is the lack of a conclusive definition of shopping behavior because of the various principles used by different healthcare systems. In addition, quantitative data that support a relationship between shopping behavior and use of healthcare services are limited, although it is obvious that the shopping behavior could induce wastefulness.

Our study focused on patients newly diagnosed with cancer in 2003 to explore the factors associated with their shopping behavior. We evaluated the definition of outpatient-shopping behavior (ie, making at least 4 or 5 physician visits to confirm a diagnosis of cancer), taking into consideration healthcare providers’ characteristics. In addition, we analyzed patients’ 5-year survival rate compared with that of nonshopping patients. These outcomes enabled us to determine the consequences of outpatient-shopping behavior and to develop feasible strategies to improve the quality of cancer care.


Data Sources

This study linked 3 databases (the Taiwan Cancer Registry, the NHI claim database, and the death registry database) to explore factors associated with outpatient-shopping behavior and to conduct survival analysis. The Taiwan Cancer Registry collects basic information on newly diagnosed cancer patients from hospitals. All hospitals are required to report cancer records, and quality controls are conducted periodically to identify possible errors and inconsistencies.1 The NHI, Taiwan’s national health insurance program, was established in 1995 and covers 99% of the population in providing comprehensive services. The NHI database, a valuable population-based database, contains substantial information on people’s use of medical services and a longitudinal time frame for cohort design. The Department of Health in Taiwan ensures the completeness and accuracy of the NHI database.19 Therefore, we linked data from the 3 databases together using patients’ identification numbers in compliance with privacy regulations. This study was approved by the Institutional Review Board of Asia University.

Study Design

Study Population and First-Time Diagnosis.
This study focused on patients newly diagnosed with 1 of the 10 most common cancers, according to the cancer registry database (restricted to patients with their first diagnosis of cancer). The cancers were selected using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) A-codes as follows: liver cancer (155, A095), lung cancer (162, A101), colorectal cancer (153, 154, A093, A094), oral cancer (140, 141, 143-146, 148, 149, A08), stomach cancer (151, A091), esophageal cancer (150, A090), prostate cancer (185, A124), pancreatic cancer (157, A096), breast cancer (174, A113), cervical cancer (179, 180, A120, A122), and other cancers not in the above list. To measure the time from first diagnosis to initiation of regular treatment, as well as the effects of patient sex, age, and income variables, we selected only patients newly diagnosed with cancer in 2003 to analyze their 5-year survival rate.

Exclusions. This study excluded patients who did not have treatment records or who had died before receiving regular treatment. We also excluded patients who were younger than 20 years because their decisions might have been influenced by their parents. Additionally, based on NHI provisions, dependents of qualified beneficiaries do not report their income to the NHI service; therefore their income would have been 0 in the database and may have distorted the estimations in this study. Figure 1 shows the patient selection process used in this study.

Regular Treatment. In most situations, when patients accept the diagnosis of cancer, they typically undergo regularly scheduled treatment. According to NHI reimbursement schemes, 4 main forms of cancer treatment are used: surgery (ICD_op_code [NHI, Taiwan coding manual], varies for different types of cancer), radiotherapy (D1), chemotherapy (D2), and drugs (12). Undergoing 1 of these 4 types of treatment after a diagnosis of cancer is considered regular treatment.

Outpatient-Shopping Behavior. We selected assessment criteria and explored the characteristics of outpatientshopping behavior using the frequency of outpatient visits. Previous studies considered seeking a second opinion on a diagnosis to be rational behavior. For this study, we defined outpatient-shopping behavior as >4 or >5 physician visits to confirm a diagnosis of cancer. Then we compared the difference between the 2 cutoff points.

Statistical Analyses. First, we determined the number of outpatient visits related to cancer from the first diagnosis until regular treatment. Then we used t tests and 1-way analysis of variance to investigate the influencing factors (age, sex, income, marriage, urbanization, Charlson Comorbidity Index score, cancer type, and severity) between the nonshopping and shopping groups. To determine differential cancer stages, we used the grading method of the Taiwan cancer registry database (well, moderate, poor, undifferentiated, and not determined), which is the method used by the International Classification of Diseases for Oncology. Additionally, logistic regression was performed to determine which factors might have been associated with outpatient-shopping behavior. Patient characteristics included age, sex, income, and cancer type; provider characteristics included the physician’s age and sex, and the level of the hospital (medical center, regional hospital, district hospital, or clinic) where the initial diagnosis was made. For patient survival analysis, we calculated the overall patient survival rates and compared the shopping and nonshopping groups on the probability of surviving or being event-free in 5 years. We focused on the time between the first diagnosis and initiation of regular treatment and did not calculate the survival days for the specific cancers.

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