Linking population-based cohorts with cancer registries in LMIC: a case study and lessons learnt in India

OBJECTIVES

In resource-constrained settings, cancer epidemiology research typically relies on self-reported diagnoses. To test a more systematic alternative approach, we assessed the feasibility of linking a cohort with a cancer registry.

SETTING

Data linkage was performed between a population-based cohort in Chennai, India, with a local population-based cancer registry.

PARTICIPANTS

Data set of Centre for Cardiometabolic Risk Reduction in South-Asia (CARRS) cohort participants (N=11 772) from Chennai was linked with the cancer registry data set for the period 1982-2015 (N=140 986).

METHODS AND OUTCOME MEASURES

Match*Pro, a probabilistic record linkage software, was used for computerised linkages followed by manual review of high scoring records. The variables used for linkage included participant name, gender, age, address, Postal Index Number and father's and spouse's name. Registry records between 2010 and 2015 and between 1982 and 2015, respectively, represented incident and all (both incident and prevalent) cases. The extent of agreement between self-reports and registry-based ascertainment was expressed as the proportion of cases found in both data sets among cases identified independently in each source.

RESULTS

There were 52 self-reported cancer cases among 11 772 cohort participants, but 5 cases were misreported. Of the remaining 47 eligible self-reported cases (incident and prevalent), 37 (79%) were confirmed by registry linkage. Among 29 self-reported incident cancers, 25 (86%) were found in the registry. Registry linkage also identified 24 previously not reported cancers; 12 of those were incident cases. The likelihood of linkage was higher in more recent years (2014-2015).

CONCLUSIONS

Although linkage variables in this study had limited discriminatory power in the absence of a unique identifier, an appreciable proportion of self-reported cases were confirmed in the registry via linkages. More importantly, the linkages also identified many previously unreported cases. These findings offer new insights that can inform future cancer surveillance and research in low-income and middle-income countries.

Feasibility and Results of Cancer Registry and Noncommunicable Disease Cohort Data Linkages in India

Background: Cancer registries worldwide are vital to determine cancer burden, plan cancer control measures, and facilitate research. Population-based cancer registries are a priority for LMICs by the UICC; the National Cancer Registry Program (NCRP) of India oversees 28 such registries. A primary function of registries is to combine data for the same individual from multiple sources. For other disease cohorts where cancer is an outcome of interest, registries can potentially connect information by linking datasets together. Barriers to successful registration and linkages include systems in which cancer is not a notifiable disease, no universal unique individual identifier exists, and lack of trained personnel. This study utilizes technology and infrastructure to develop better linkages, surveillance, and outcomes. Aim: To assess the feasibility of linking large cohorts designed for cardio-metabolic disease research with cancer registries in New Delhi and Chennai; determine additional steps required for linkage accuracy and completeness; and develop detailed protocols for future applications. Methods: A pilot protocol for linkage between a large diabetes cohort and cancer registries in Delhi and Chennai was developed using MatchPro, a probabilistic record linkage program developed for cancer registries. Probabilistic software links datasets together in the presence of uncertainty (eg misspelled or abbreviated names) to identify record pairs with high probability of representing the same individual. For this study, algorithms were developed to address unique aspects of names and demographics in India. The software and algorithms focused on: detecting duplicates in cancer registries; and linking registries with external files from diabetes cohorts. In Delhi, 3 1-year datasets covering 3 years (2010, 2011, 2012) were linked with the diabetes cohort; in Chennai, the linkage included 3 5-year datasets covering 15 years (2000-04, '05-'09, '10-'14). The unique ID (Aadhaar) is not collected or linked systematically between different systems at this point in time. Results: Linkage attempts yielded potential matches ranked according to probabilistic scores; highest scores were reviewed to determine true matches. In Chennai, this process yielded: (2010-2014) 21% self-reported (SR) cases matching perfectly, 36% requiring follow-up, 13 nonreported (NR) cases found; 2005-2009: 33% SR cases matched perfectly, 1 NR case found; 2000-2004: 1 NR case. Also, 2 training workshops on data linkages and software were held. Conclusion: Linkages between cancer registries and other data sources are feasible in LMICs using probabilistic record linkage software augmented by manual matching. Future efforts to use existing epidemiologic resources (cohorts) and cancer research infrastructure (registries and clinical centers) can enhance research including understanding shared risk factors and pathophysiologic mechanisms e.g., between cancer and other NCD.

Multiple Stakeholder Perspectives on Cancer Stigma in North India

BACKGROUND

Cancer is a leading cause of death worldwide. A large proportion of cancer deaths are preventable through early detection but there are a range of social, emotional, cultural and financial dimensions that hinder the effectiveness of cancer prevention and treatment efforts. Cancer stigma is one such barrier and is increasingly recognized as an important factor influencing health awareness and promotion, and hence, disease prevention and control. The impact and extent of stigma on the cancer early detection and care continuum is poorly understood in India.

OBJECTIVES

To evaluate cancer awareness and stigma from multiple stakeholder perspectives in North India, including men and women from the general population, health care professionals and educators, and cancer survivors.

MATERIALS AND METHODS

A qualitative study was conducted with in-depth interviews (IDIs) and focus group discussions (FGDs) among 39 individuals over a period of 3 months in 2014. Three groups of participants were chosen purposively - 1) men and women who attended cancer screening camps held by the Indian Cancer Society, Delhi; 2) health care providers and 3) cancer survivors.

RESULTS

Most participants were unaware of what cancers are in general, their causes and ways of prevention. Attitudes of families towards cancer patients were observed to be positive and caring. Nevertheless, stigma and its impact emerged as a cross cutting theme across all groups. Cost of treatment, lack of awarenes and beliefs in alternate medicines were identified as some of the major barriers to seeking care.

CONCLUSIONS

This study suggests a need for spreading awareness, knowledge about cancers and assessing associated impact among the people. Also Future research is recommended to help eradicate stigma from the society and reduce cancer-related stigma in the Indian context.

Cancer detection rates in a population-based, opportunistic screening model, New Delhi, India

BACKGROUND

In India, cancer accounts for 7.3% of DALY's, 14.3% of mortality with an age-standardized incident rate of 92.4/100,000 in men and 97.4/100,000 in women and yet there are no nationwide screening programs.

MATERIALS AND METHODS

We calculated age-standardized and age-truncated (30-69 years) detection rates for men and women who attended the Indian Cancer Society detection centre, New Delhi from 2011-12. All participants were registered with socio-demographic, medical, family and risk factors history questionnaires, administered clinical examinations to screen for breast, oral, gynecological and other cancers through a comprehensive physical examination and complete blood count. Patients with an abnormal clinical exam or blood result were referred to collaborating institutes for further investigations and follow-up.

RESULTS

A total of n=3503 were screened during 2011-12 (47.8% men, 51.6% women and 0.6% children <15 years) with a mean age of 47.8 yrs (±15.1 yrs); 80.5% were aged 30-69 years and 77.1% had at least a secondary education. Tobacco use was reported by 15.8%, alcohol consumption by 11.9% and family history of cancer by 9.9% of participants. Follow-up of suspicious cases yielded 45 incident cancers (51.1% in men, 48.9% in women), consisting of 55.5% head and neck (72.0% oral), 28.9% breast, 6.7% gynecological and 8.9% other cancer sites. The age-standardized detection rate for all cancer sites was 340.8/100,000 men and 329.8/100,000 women.

CONCLUSIONS

Cancer screening centres are an effective means of attracting high-risk persons in low-resource settings. Opportunistic screening is one feasible pathway to address the rising cancer burden in urban India through early detection.

Impact of dental considerations on the quality of life of oral cancer patients

Aim:

To evaluate the significance of pre-treatment dental care in oral cancer patients and to assess its impact on the quality of life of these patients.

Materials and Methods:

The sample size included 50 oral cancer patients who were visiting to a palliative care unit at Jaipur. Assessment was based on thorough case history, complete dental examination. Quality of life was estimated by W.H.O quality of life questionnaire.

Result:

On analysis, patients of age group 50-59 avoided to prophylactic dental treatment before cancer treatment and therapy. Seventy-eight percent patients experienced worst quality of life after the treatment as a result of dental complications. Out of those 78%, only 2% of patients took preventive dental treatments before the cancer therapy.

Conclusion:

Dental negligence is still a major cause of worsening of post treatment quality of life of an individual. Therefore, the treating oncologist should always take these considerations seriously to provide quality treatment to the patient.

Digital dental photography: a contemporary revolution

Introduction: Photographs are symbolic of memories and with the advent of digital photography it has become much easier to collect them in a second in a more comprehensive and qualitative manner. Technological advancements in the field of digital photography have revolutionized the concept of photography as a powerful medium of expression and communication. It also offers a spectrum of perception, interpretation and execution. Photography and dentistry go hand in hand for revelation of the hidden and overlooked defects in teeth and other parts of the cavity. This article emphasizes on the significance of digital photography in dentistry and guidelines for capturing orofacial structures and radiographs in a more accurate and informative manner.

Conclusion: Dental world constitutes of microstructures that have to be recorded in a detailed manner in order to perform patient education, documentation of records and treatment, illustration of lectures, publication and web connectivity of complicated cases.

How to cite this article: Desai V, Bumb D. Digital Dental Photography: A Contemporary Revolution. Int J Clin Pediatr Dent 2013;6(3):193-196.