What is population health intervention research?

International migration to Canada: the post-birth health of mothers and infants by immigration class

There are over 214 million international migrants worldwide, half of whom are women, and all of them assigned by the receiving country to an immigration class. Immigration classes are associated with certain health risks and regulatory restrictions related to eligibility for health care. Prior to this study, reports of international migrant post-birth health had not been compared between immigration classes, with the exception of our earlier, smaller study in which we found asylum-seekers to be at greatest risk for health concerns. In order to determine whether refugee or asylum-seeking women or their infants experience a greater number or a different distribution of professionally-identified health concerns after birth than immigrant or Canadian-born women, we recruited 1127 migrant (and in Canada <5 years) women-infant pairs, defined by immigration class (refugee, asylum-seeker, immigrant, or Canadian-born). Between February 2006 and May 2009, we followed them from childbirth (in one of eleven birthing centres in Montreal or Toronto) to four months and found that at one week postpartum, asylum-seeking and immigrant women had greater rates of professionally-identified health concerns than Canadian-born women; and at four months, all three migrant groups had greater rates of professionally-identified concerns. Further, international migrants were at greater risk of not having these concerns addressed by the Canadian health care system. The current study supports our earlier findings and highlights the need for case-finding and services for international migrant women, particularly for psychosocial difficulties. Policy and program mechanisms to address migrants' needs would best be developed within the various immigration classes.

Frequently asked questions about population health intervention research

Population health intervention research requires stronger definition. There are overlaps and differences between it and established domains such as evaluation, health impact assessment, knowledge translation, health services research, and social and public policy analysis. The value added of this growing field is its potential to draw more resources as well as diverse expertise, methods and ways of knowing under one umbrella at a critical time in history. That is, at a time when actions to reduce health inequities have become paramount.

Frequently asked questions about population health intervention research

Population health intervention research requires stronger definition. There are overlaps and differences between it and established domains such as evaluation, health impact assessment, knowledge translation, health services research, and social and public policy analysis. The value added of this growing field is its potential to draw more resources as well as diverse expertise, methods and ways of knowing under one umbrella at a critical time in history. That is, at a time when actions to reduce health inequities have become paramount.

Modelling the social determinants of health and simulating short-term and long-term intervention impacts for the city of Toronto, Canada

There is a substantial body of evidence highlighting the importance of the social determinants of health in shaping the health of urban populations in Canada. The low socio-economic status of marginalized, disadvantaged, and precarious populations in urban settings has been linked to adverse health outcomes including chronic and infectious disease, negative health behaviours, barriers to accessing health care services, and overall mortality. Given the dynamic complexities and inter-relationships surrounding the underlying drivers of population health outcomes and inequities, it is difficult to assess program and policy intervention tradeoffs, particularly when such interventions are studied with static models. To address this challenge, we have adopted a systems science approach and developed a simulation model for the City of Toronto, Canada, utilizing system dynamics modelling methodology. The model simulates changes in health, social determinants, and disparities from 2006 and projects forward to 2046 under different assumptions. Most of the variables in the model are stratified by ethnicity, immigration status, and gender, and capture the characteristics of adults aged 25-64. Intervention areas include health care access, behaviour, income, housing, and social cohesion. The model simulates alternative scenarios to help demonstrate the relative impact of different interventions on poor health outcomes such as chronic disease rates, disability rates, and mortality rate. It gives insight into how much, and how quickly, interventions can reduce mortality and morbidity. We believe this will serve as a useful learning tool to allow diverse stakeholders and policy makers to ask "what if" questions and map effective policy directions for complex population health problems, and will enable communities to think about their health futures.

Epilogue: a critical look at a nascent field

A broad coalition of partners, entitled PHIRIC (Population Health Intervention Research Initiative for Canada), are working to increase the amount/quality of population health intervention research (PHIR) in our country. A central theme is to advance the science in this area. The current CJPH Supplement is welcomed as a set of diverse studies done to further our understanding of PHIR. The papers illustrate the range of questions that can be addressed and the variety of methods that need to be utilized. There is a need for critical reflection on three questions: 1) what constitutes PHIR? 2) which intervention parameters can be researched? and 3) what methods are recognized by the research community? Although legitimate attempts to define PHIR exist, the boundaries remain elusive. (Even the choice of articles in the current Supplement might be questioned.) It has cogently been argued that 'true' public health interventions intend to change risk conditions and alter distributions of health risk. This commentary suggests an important amendment to prior evaluation questions in stating that PHIR must pay attention to how intervention outcomes are distributed. There are also questions inherent in assessing the equity and distribution of an outcome. The bottom line is that we need to spread the word: more research is needed.

Epilogue: a critical look at a nascent field

A broad coalition of partners, entitled PHIRIC (Population Health Intervention Research Initiative for Canada), are working to increase the amount/quality of population health intervention research (PHIR) in our country. A central theme is to advance the science in this area. The current CJPH Supplement is welcomed as a set of diverse studies done to further our understanding of PHIR. The papers illustrate the range of questions that can be addressed and the variety of methods that need to be utilized. There is a need for critical reflection on three questions: 1) what constitutes PHIR? 2) which intervention parameters can be researched? and 3) what methods are recognized by the research community? Although legitimate attempts to define PHIR exist, the boundaries remain elusive. (Even the choice of articles in the current Supplement might be questioned.) It has cogently been argued that 'true' public health interventions intend to change risk conditions and alter distributions of health risk. This commentary suggests an important amendment to prior evaluation questions in stating that PHIR must pay attention to how intervention outcomes are distributed. There are also questions inherent in assessing the equity and distribution of an outcome. The bottom line is that we need to spread the word: more research is needed.

A ban on marketing of foods/beverages to children: the who, why, what and how of a population health intervention

There is increasing recognition in Canada and elsewhere of the need for population-level interventions related to diet. One example of such an intervention is a ban on the marketing of foods/beverages to children, for which several health organizations have or are in the process of developing position statements. Considering the federal government's inaction to impose restrictions that would yield meaningful impact, there is opportunity for the health community to unite in support of a stronger set of policies. However, several issues and challenges exist, some of which we outline in this commentary. We emphasize that, despite challenges, the present and predicted future of diet-related illness in Canadian children is such that population-level intervention is necessary and becoming increasingly urgent, and there is an important role for the health community in facilitating action.

Exploring the value of mixed methods within the At Home/Chez Soi housing first project: a strategy to evaluate the implementation of a complex population health intervention for people with mental illness who have been homeless

OBJECTIVE

This paper is a methodological case study that describes the At Home/Chez Soi (Housing First) Initiative's mixed-methods strategy for implementation evaluation and discusses the value of these methods in evaluating the implementation of such complex population health interventions.

TARGET POPULATION

The Housing First (HF) model is being implemented in five cities: Vancouver, Winnipeg, Toronto, Montréal and Moncton.

INTERVENTION

At Home/Chez Soi is an intervention trial that aims to address the issue of homelessness in people with mental health issues. The HF model emphasizes choices, hopefulness and connecting people with resources that make a difference to their quality of life. A component of HF is supported housing, which provides a rent subsidy and rapid access to housing of choice in private apartments; a second component is support. Quantitative and qualitative methods were used to evaluate HF implementation.

OUTCOMES

The findings of this case study illustrate how the critical ingredients of complex interventions, such as HF, can be adapted to different contexts while implementation fidelity is maintained at a theoretical level. The findings also illustrate how the project's mixed methods approach helped to facilitate the adaptation process. Another value of this approach is that it identifies systemic and organizational factors (e.g., housing supply, discrimination, housing procurement strategy) that affect implementation of key elements of HF.

CONCLUSION

In general, the approach provides information about both whether and how key aspects of the intervention are implemented effectively across different settings. It thus provides implementation data that are rigorous, contextually relevant and practical.

Exploring the value of mixed methods within the At Home/Chez Soi housing first project: a strategy to evaluate the implementation of a complex population health intervention for people with mental illness who have been homeless

OBJECTIVE

This paper is a methodological case study that describes the At Home/Chez Soi (Housing First) Initiative's mixed-methods strategy for implementation evaluation and discusses the value of these methods in evaluating the implementation of such complex population health interventions.

TARGET POPULATION

The Housing First (HF) model is being implemented in five cities: Vancouver, Winnipeg, Toronto, Montréal and Moncton.

INTERVENTION

At Home/Chez Soi is an intervention trial that aims to address the issue of homelessness in people with mental health issues. The HF model emphasizes choices, hopefulness and connecting people with resources that make a difference to their quality of life. A component of HF is supported housing, which provides a rent subsidy and rapid access to housing of choice in private apartments; a second component is support. Quantitative and qualitative methods were used to evaluate HF implementation.

OUTCOMES

The findings of this case study illustrate how the critical ingredients of complex interventions, such as HF, can be adapted to different contexts while implementation fidelity is maintained at a theoretical level. The findings also illustrate how the project's mixed methods approach helped to facilitate the adaptation process. Another value of this approach is that it identifies systemic and organizational factors (e.g., housing supply, discrimination, housing procurement strategy) that affect implementation of key elements of HF.

CONCLUSION

In general, the approach provides information about both whether and how key aspects of the intervention are implemented effectively across different settings. It thus provides implementation data that are rigorous, contextually relevant and practical.

A ban on marketing of foods/beverages to children: the who, why, what and how of a population health intervention

There is increasing recognition in Canada and elsewhere of the need for population-level interventions related to diet. One example of such an intervention is a ban on the marketing of foods/beverages to children, for which several health organizations have or are in the process of developing position statements. Considering the federal government's inaction to impose restrictions that would yield meaningful impact, there is opportunity for the health community to unite in support of a stronger set of policies. However, several issues and challenges exist, some of which we outline in this commentary. We emphasize that, despite challenges, the present and predicted future of diet-related illness in Canadian children is such that population-level intervention is necessary and becoming increasingly urgent, and there is an important role for the health community in facilitating action.

Drinking water fluoridation and oral health inequities in Canadian children

OBJECTIVES

One argument made in favour of drinking water fluoridation is that it is equitable in its impact on oral health. We examined the association between exposure to fluoridation and oral health inequities among Canadian children.PARTICIPANTS, SETTING AND INTERVENTION: We analyzed data from 1,017 children aged 6-11 from Cycle 1 of the Canadian Health Measures Survey, a cross-sectional, nationally representative survey that included a clinic oral health examination and a household interview. The outcome measure was a count of the number of decayed, missing (because of caries or periodontal disease) or filled teeth, either deciduous or permanent (dmftDMFT). Data were analyzed using linear (ordinary least squares) and multinomial logistic regression; we also computed the concentration index for education-related inequity in oral health. Water fluoridation status (the intervention) was assigned on the basis of the site location of data collection.

OUTCOMES

Fluoridation was associated with better oral health (fewer dmftDMFT), adjusting for socio-economic and behavioural variables, and the effect was particularly strong for more severe oral health problems (three or more dmftDMFT). The effect of fluoridation on dmftDMFT was observed across income and education categories but appeared especially pronounced in lower education and higher income adequacy households. dmftDMFT were found to be disproportionately concentrated in lower-education households, though this did not vary by fluoridation status.

CONCLUSIONS

The robust main effect of fluoridation on dmftDMFT and the beneficial effect across socio-economic groups support fluoridation as a beneficial and justifiable population health intervention. Fluoridation was equitable in the sense that its benefits were particularly apparent in those groups with the poorest oral health profiles, though the nature of the findings prompts consideration of the values underlying the judgement of health equity.

Drinking water fluoridation and oral health inequities in Canadian children

OBJECTIVES

One argument made in favour of drinking water fluoridation is that it is equitable in its impact on oral health. We examined the association between exposure to fluoridation and oral health inequities among Canadian children.PARTICIPANTS, SETTING AND INTERVENTION: We analyzed data from 1,017 children aged 6-11 from Cycle 1 of the Canadian Health Measures Survey, a cross-sectional, nationally representative survey that included a clinic oral health examination and a household interview. The outcome measure was a count of the number of decayed, missing (because of caries or periodontal disease) or filled teeth, either deciduous or permanent (dmftDMFT). Data were analyzed using linear (ordinary least squares) and multinomial logistic regression; we also computed the concentration index for education-related inequity in oral health. Water fluoridation status (the intervention) was assigned on the basis of the site location of data collection.

OUTCOMES

Fluoridation was associated with better oral health (fewer dmftDMFT), adjusting for socio-economic and behavioural variables, and the effect was particularly strong for more severe oral health problems (three or more dmftDMFT). The effect of fluoridation on dmftDMFT was observed across income and education categories but appeared especially pronounced in lower education and higher income adequacy households. dmftDMFT were found to be disproportionately concentrated in lower-education households, though this did not vary by fluoridation status.

CONCLUSIONS

The robust main effect of fluoridation on dmftDMFT and the beneficial effect across socio-economic groups support fluoridation as a beneficial and justifiable population health intervention. Fluoridation was equitable in the sense that its benefits were particularly apparent in those groups with the poorest oral health profiles, though the nature of the findings prompts consideration of the values underlying the judgement of health equity.

Adaptation and implementation of the nurse-family partnership in Canada

OBJECTIVES

International agencies are required to adapt, pilot and then evaluate the effectiveness of the Nurse-Family Partnership (NFP) prior to broad implementation of this public health intervention. The objectives of this qualitative case study were to: 1) determine whether the NFP can be implemented in Canada with fidelity to the US model, and 2) identify the adaptations required to increase the acceptability of the intervention for service providers and families.

PARTICIPANTS

108 low-income, first-time mothers in Hamilton, Ontario, received the NFP intervention. In-depth interviews were conducted with NFP clients (n=38), family members (n=14) and community professionals (n=24).

SETTING

Hamilton, Ontario.INTERVENTION AND DATA COLLECTION: An intensive nurse home visitation program delivered to women starting early in pregnancy and continuing until the child was two years old. Processes to adapt and implement the NFP were explored across seven focus groups with public health nurses and managers. Eighty documents were reviewed to identify implementation challenges. Data were analyzed using directed content analysis.

OUTCOMES

The NFP model elements are acceptable to Canadian health care providers, public health nurses and families receiving the intervention. The primary adaptation required was to reduce nurse caseloads from 25 to 20 active clients. Recommendations for adapting and implementing all model elements are described.

CONCLUSION

The NFP model requires minor adaptations to increase the acceptability of the intervention to Canadian stakeholders. A consistent approach to adapting the NFP program in Canada is necessary as provincial jurisdictions commit themselves to supporting an experimental evaluation of the effectiveness of the NFP.

Adaptation and implementation of the nurse-family partnership in Canada

OBJECTIVES

International agencies are required to adapt, pilot and then evaluate the effectiveness of the Nurse-Family Partnership (NFP) prior to broad implementation of this public health intervention. The objectives of this qualitative case study were to: 1) determine whether the NFP can be implemented in Canada with fidelity to the US model, and 2) identify the adaptations required to increase the acceptability of the intervention for service providers and families.

PARTICIPANTS

108 low-income, first-time mothers in Hamilton, Ontario, received the NFP intervention. In-depth interviews were conducted with NFP clients (n=38), family members (n=14) and community professionals (n=24).

SETTING

Hamilton, Ontario.INTERVENTION AND DATA COLLECTION: An intensive nurse home visitation program delivered to women starting early in pregnancy and continuing until the child was two years old. Processes to adapt and implement the NFP were explored across seven focus groups with public health nurses and managers. Eighty documents were reviewed to identify implementation challenges. Data were analyzed using directed content analysis.

OUTCOMES

The NFP model elements are acceptable to Canadian health care providers, public health nurses and families receiving the intervention. The primary adaptation required was to reduce nurse caseloads from 25 to 20 active clients. Recommendations for adapting and implementing all model elements are described.

CONCLUSION

The NFP model requires minor adaptations to increase the acceptability of the intervention to Canadian stakeholders. A consistent approach to adapting the NFP program in Canada is necessary as provincial jurisdictions commit themselves to supporting an experimental evaluation of the effectiveness of the NFP.

A media advocacy intervention linking health disparities and food insecurity

Media advocacy is a well-established strategy for transmitting health messages to the public. This paper discusses a media advocacy intervention that raised issues about how the public interprets messages about the negative effects of poverty on population health. In conjunction with the publication of a manuscript illustrating how income-related food insecurity leads to disparities related to the consumption of a popular food product across Canada (namely, Kraft Dinner®), we launched a media intervention intended to appeal to radio, television, print and Internet journalists. All the media coverage conveyed our intended message that food insecurity is a serious population health problem, confirming that message framing, personal narratives and visual imagery are important in persuading media outlets to carry stories about poverty as a determinant of population health. Among politicians and members of the public (through on-line discussions), the coverage provoked on-message as well as off-message reactions. Population health researchers and health promotion practitioners should anticipate mixed reactions to media advocacy interventions, particularly in light of new Internet technologies. Opposition to media stories regarding the socio-economic determinants of population health can provide new insights into how we might overcome challenges in translating evidence into preventive interventions.

An agriculture and health inter-sectorial research process to reduce hazardous pesticide health impacts among smallholder farmers in the Andes

BACKGROUND

The use of highly hazardous pesticides by smallholder farmers constitutes a classic trans-sectoral 'wicked problem'. We share our program of research in potato and vegetable farming communities in the Andean highlands, working with partners from multiple sectors to confront this problem over several projects.

METHODS

We engaged in iterative cycles of mixed methods research around particular questions, actions relevant to stakeholders, new proposal formulation and implementation followed by evaluation of impacts. Capacity building occurred among farmers, technical personnel, and students from multiple disciplines. Involvement of research users occurred throughout: women and men farmers, non-governmental development organizations, Ministries of Health and Agriculture, and, in Ecuador, the National Council on Social Participation.

RESULTS

Pesticide poisonings were more widespread than existing passive surveillance systems would suggest. More diversified, moderately developed agricultural systems had lower pesticide use and better child nutrition. Greater understanding among women of crop management options and more equal household gender relations were associated with reduced farm pesticide use and household pesticide exposure. Involvement in more organic agriculture was associated with greater household food security and food sovereignty. Markets for safer produce supported efforts by smallholder farmers to reduce hazardous pesticide use.Participatory interventions included: promoting greater access to alternative methods and inputs in a store co-sponsored by the municipality; producing less harmful inputs such as compost by women farmers; strengthening farmer organizations around healthier and more sustainable agriculture; marketing safer produce among social sectors; empowering farmers to act as social monitors; and using social monitoring results to inform decision makers. Uptake by policy makers has included: the Ecuadorian Ministry of Health rolling out pesticide poisoning surveillance modeled on our system; the Ecuadorian Association of Municipalities holding a national virtual forum on healthier agriculture; and the Ecuadorian Ministry of Agriculture promulgating restrictions on highly hazardous pesticides in June 2010.

CONCLUSION

Work with multiple actors is needed to shift agriculture towards greater sustainability and human health, particularly for vulnerable smallholders.

Municipal bylaw to reduce cosmetic/non-essential pesticide use on household lawns - a policy implementation evaluation

BACKGROUND

Pesticide use on urban lawns and gardens contributes to environmental contamination and human exposure. Municipal policies to restrict use and educate households on viable alternatives deserve study. We describe the development and implementation of a cosmetic/non-essential pesticide bylaw by a municipal health department in Toronto, Ontario, Canada and assess changes in resident practices associated with bylaw implementation.

METHODS

Implementation indicators built on a logic model and were elaborated through key informant interviews. Bylaw impacts on awareness and practice changes were documented through telephone surveys administered seasonally pre, during and post implementation (2003-2008). Multivariable logistic regression models assessed associations of demographic variables and gardening season with respondent awareness and practices.

RESULTS

Implementation indicators documented multiple municipal health department activities and public involvement in complaints from commencement of the educational phase. During the enforcement phases only 40 warning letters and 7 convictions were needed. The number of lawn care companies increased. Among survey respondents, awareness of the bylaw and the Natural Lawn campaign reached 69% and 76% respectively by 2008. Substantial decreases in the proportion of households applying pesticides (25 to 11%) or hiring lawn care companies for application (15 to 5%) occurred. Parallel absolute increases in use of natural lawn care methods occurred among households themselves (21%) and companies they contracted (7%).

CONCLUSIONS

Bylaws or ordinances implemented through education and enforcement are a viable policy option for reducing urban cosmetic pesticide use.

Population Health Intervention Research Initiative for Canada: progress and prospects

Actions in Canada are being designed to transform the way research evidence is generated and used to improve population health. Capacity is being built in population health intervention research. The primary target is more understanding and examination of policies and programs that could redress inequities in health. The Population Health Intervention Research Initiative for Canada is a loosely-networked collaboration designed to advance the science of the field as well as the quantity, quality and use of population health intervention research to improve the health of Canadians. In the first few years there have been new training investments, new funding programs, new working guidelines for peer review, symposia and new international collaborations. This has been brought about by the strategic alignment of communication, planning and existing investments and the leveraging of new resources.

Reflections on community-based population health intervention and evaluation for obesity and chronic disease prevention: the Healthy Alberta Communities project

OBJECTIVES

To reflect upon a population health intervention for obesity and chronic disease prevention, with specific attention to the processes of change and developing, implementing and evaluating an intervention in a community-university-government partnership context.

METHODS

To capture the value, process and context of our interventions, we employed a multi-layered, mixed methods research and evaluation design. Guided by assumptions of community-based participatory research, and using a validated capacity-building tool, the investigators described and reflected critically upon the level and nature of capacity built (for both research and intervention) as indicators of the process and contextual influences on intervention success.

RESULTS

Capacity was built in communities through collaborative approaches. We captured complexity of change in social context to advance understanding of how to intervene to transform environments. Developing novel community evaluation strategies can help to advance understanding of how environmental interventions affect health before health outcomes data demonstrate change.

CONCLUSIONS

Our experience provides an example of operationalizing an ecological framework. As a community-university-government partnership, Healthy Alberta Communities provides an opportunity for developing promising practices for the health of communities, as well as a unique research platform for evaluating the process and establishing effectiveness of population health interventions.

A systematic review of population health interventions and Scheduled Tribes in India

Background

Despite India's recent economic growth, health and human development indicators of Scheduled Tribes (ST) or Adivasi (India's indigenous populations) lag behind national averages. The aim of this review was to identify the public health interventions or components of these interventions that are effective in reducing morbidity or mortality rates and reducing risks of ill health among ST populations in India, in order to inform policy and to identify important research gaps.

Methods

We systematically searched and assessed peer-reviewed literature on evaluations or intervention studies of a population health intervention undertaken with an ST population or in a tribal area, with a population health outcome(s), and involving primary data collection.

Results

The evidence compiled in this review revealed three issues that promote effective public health interventions with STs: (1) to develop and implement interventions that are low-cost, give rapid results and can be easily administered, (2): a multi-pronged approach, and (3): involve ST populations in the intervention.

Conclusion

While there is a growing body of knowledge on the health needs of STs, there is a paucity of data on how we can address these needs. We provide suggestions on how to undertake future population health intervention research with ST populations and offer priority research avenues that will help to address our knowledge gap in this area.

Characteristics of urban parks associated with park use and physical activity: a review of qualitative research

Given that recent literature reviews on physical activity in urban parks deliberately excluded qualitative findings, we reviewed qualitative research on this topic informed by a published classification scheme based on quantitative research. Twenty-one studies met our inclusion criteria. These studies relied mainly on semi-structured interviews with individuals or in focus groups; only five studies involved in situ observation. Our synthesis aligns with previous quantitative research showing that attributes including safety, aesthetics, amenities, maintenance, and proximity are important for encouraging park use. Furthermore, our synthesis of qualitative research suggests that perceptions of the social environment entwine inextricably with perceptions of the physical environment. If so, physical attributes of parks as well as perceptions of these attributes (formed in relation to broader social contexts) may influence physical activity patterns. Both qualitative and quantitative methods provide useful information for interpreting such patterns, and in particular, when designing and assessing interventions intended to improve the amount and intensity of physical activity.