Factors related with symptom duration until diagnosis and treatment of symptomatic colorectal cancer

This paper reports findings from a larger study whose methods have been published elsewhere [17]. This is a cross-sectional study carried out in 5 Spanish regions. Briefly, subjects were consecutive incident cases of CRC (IDC9 153 and 154), verified histologically, between September 2006 and September 2008 and registered with a GP. Prevalent or recurrent cases were excluded as well as patients with multiple tumors and those diagnosed in private hospitals. For the present analysis, non-symptomatic patients were also excluded (screening detected cases, incidental findings).

Patients were identified at diagnosis through results of histological findings from endoscopy or surgery and contacted during the inpatient stage or oncology visit by their surgeon or oncologist who invited them to participate.

Data were obtained from patient interviews together with primary care and hospital clinical records review. Each of the patients was interviewed after diagnosis using a structured questionnaire during the inpatient stage, oncology visit or, if this were not possible, at home by a trained nurse or GP. Informed consent for study participation and access to medical records was obtained during the interview. In cases where the patient was deceased or could not be interviewed for other reasons, permission to review patient clinical records was obtained from a close family member. Details about measurements can be found in Additional file 1.

Interview measurements: Each patient was asked how long he/she had been feeling unwell and given a checklist to identify the type of symptom/s noted [18]. Symptoms spontaneously mentioned by the patient were considered the initial symptom/s for that patient and the date was recorded. Additional presenting symptoms were recorded. Other variables were social class [19] and demographic characteristics, perception of symptom seriousness, disclosure of symptoms, help-seeking action, doctor-patient relationship, and familial history of cancer. Primary care measurements were: date of first symptom and other symptoms, date of first contact with GP due to CRC symptoms, examinations and visits before diagnosis and their results, and date and information included in the referral. Hospital record measurements were: tumor data, date of first symptom and other symptoms, intestinal obstruction, date of first contact due to CRC symptoms, date of diagnosis, service attending the patient, examinations and visits before diagnosis and their results, and date and type of treatment.

Symptom Diagnosis Interval (SDI): from onset of first CRC symptoms to date of diagnosis.

Symptom Treatment Interval (STI): from onset of first CRC symptoms until start of treatment.

Patient Interval (PI): from onset of first CRC symptoms to date of first consultation with a physician (GP or hospital specialist).

Health Services Interval (HSI): Interval from 1st contact with a physician to diagnosis.

Treatment interval (TI): Interval from date of diagnosis to date of treatment.

In order to calculate time intervals, it was necessary to establish several definitions:

Date of onset of the first symptom/s was the one referred to by the patient. In the case of no interview, the date of 1st symptom recorded in the primary health care record or in the hospital record was used.

Date of diagnosis, i.e., date of first positive histology report. Date of treatment, i.e., date of surgery, date of preoperative or postoperative radiotherapy or chemotherapy or date of palliative treatment. For those patients who did not receive any treatment, the date of the visit closest to the decision not to treat the patient was recorded.

The graphical analysis of interval times showed skewed distributions confirmed with the Kolmogorov-Smirnov test. Diagnosis or treatment intervals are presented as median and 25–75 percentiles. To assess the relationship between the different types of symptom interval duration and the observed variables, we used the Mann–Whitney U test for dichotomous variables and Kruskal-Wallis test for those variables with more than two categories. In order to avoid symptoms that could not be related to CRC, no more than a 24-month interval between symptom and diagnosis was accepted. Nineteen patients (0.3%) had a SDI of 24 months and twenty-one (0.7%) in the case of STI. All statistical analyses were performed using SPSS v.15.0.

This Study was approved by the Primary Health Care Committee of each health district and by the Ethical and Clinical Research Committee of each participating region.

In contrast with previous studies limited to the assessment of partial time intervals to diagnosis or treatment (patient or system time intervals), we have been able to show that these factors also affect total time to diagnosis or treatment. Our findings show a similar relationship for time to diagnosis and time to treatment with the various factors studied. This fact demonstrates that the variables considered in this study have great influence on the time to diagnosis and, as a matter of fact, duration between diagnosis and treatment is relatively less relevant (>65% of those diagnosed are treated within a month). The inclusion of a high number of hospitals and primary care centers could imply high heterogeneity in data acquisition, but at the same time represents a complete picture of patterns of care, preventing the selection bias that appears when only a single centre is included.

The major limitation of this study lies in the lack of a consistent methodology to precisely measure the date of symptom presentation. The date of onset of symptoms obtained from the patient interview has been questioned. According to some authors, studies fail to consider existing theories of symptom interpretation. The interpretation of bodily sensations as symptoms is embedded within a social and cultural context and respondents do not define time periods in the same way [46]. Therefore, this date may be quite precise for acute symptoms, such as rectal bleeding, but difficult to establish for more general symptoms such as fatigue [47]. However, other studies have shown good agreement when comparing information expressed by patients and doctors [18, 48]. Retrospective review of clinical records presents the same type of problem because it comes from patient information provided to doctors. Furthermore, some of the symptoms described to doctors may go unrecorded, as highlighted by some authors [49, 50]. Patient interviews conducted during pre or post first treatment could result in memory biases. The Aarhus statement will facilitate standardized and uniform definition of studies in this area [51]. Finally, a trusting relationship with the GP, recorded after diagnosis, could be spurious as, patient faith in their GP, could be related to lag time to diagnosis or treatment [52, 53].

Research is needed to develop interventions for use by primary and secondary care doctors to reduce diagnostic and treatment time intervals. Gender differences encountered in our population also deserve to be investigated more thoroughly. Further research into first-symptom presentation and concordance between patients and primary and hospital clinical records would give further insights into methodological issues in cancer delay studies.

The results of this work reveal the existence of areas for improvement in health care delivered to patients. Particularly important is to introduce changes to the existing guidelines whereby physical examination and laboratory and image investigations are carried out on all those who present with lower gastrointestinal symptoms independently of age, gender or symptom duration. This would also favour thorough information being included in the referral letter. If time to diagnosis is to be reduced, there must be development of interventions and guidelines to ensure appropriate diagnosis and examination during both primary and hospital care.