This assignment will be explored in two sections:
- The first section will briefly introduce mental health post natal depression, the article explored and the critical appraisal of the article using the EVERS et al., 2005 CHEC-List.
- The second section of the assignment will explain some of the difficulties associated with carrying out an economic evaluation.
The theoretical approaches will also be discussed in order to explain why it is difficult to evaluate effectiveness and cost effectiveness of complex public health interventions in the community.
The World Health Organisation defines mental health as a “state of well-being in which every individual realises his or her own potential, can cope with the normal stresses of life, can work productively and fruitfully, and is able to make a contribution to her or his community (WHO, 2016)
There are many types of mental health disorders, among them is depression- which is expected to be the second leading cause of general health problem by 2020 (Murray and Lopez 1996 cited in Paulden et al., 2009). Globally, 350 million people of all ages suffer from depression. Severe cases of depression can lead to serious health conditions and or suicide (Over 800 000 people die due to suicide every year- suicide is the second leading cause of death in 15-29-year-olds (WHO, 2016). More women are affected by depression than men.
Post natal depression is a type of depression some women experience after having a baby (NHS, 2016). Depression can cause the affected, in this case, women after birth to suffer greatly and function poorly in her day to day life. As the rise of depression and other mental health conditions is on the rise globally. The World Health Organisation (WHO) has called for a comprehensive, coordinated response to mental disorders at country level (WHO, 2013). Prevention programmes have shown to reduce depression (WHO, 2016).
The article being explored is about the cost effectiveness analysis of screening for post-natal depression in primary care. The main objective of the study was to evaluate the cost effectiveness of routine screening for postnatal depression in primary care. The main economic evaluation tool used was the Cost Effectiveness Analysis (CEA). CEA is an evaluation in which all costs and consequences of a programme are expressed as cost per unit of health outcome (Jackson, 2012 pg 111). The limitation of using CEA is that it does not allow comparisons to be made between courses of action that have completely different therapeutic outcomes (Haycoz, 2009).
In the article, the study population is clearly defined as a hypothetical population of women assessed for post natal depression either via routine care only or supplemented by the use of formal identification methods six weeks postnatally, as recommended in recent guidelines (Paulden et al., 2009). However, the ages of these women is not known. We also do not know the location or place of the study- that is if the participants where from all over England or a specific part of England.
This could help us to compare different age groups, races and location. Therefore according to Evers et al., 2005 checklist the article has not clearly described the competing alternatives in terms of their participants. They mentioned alternative methods in terms of their design as “CEA with a decision model of alternative methods of screening for depression, including standardised postnatal depression and generic depression instruments” (Paulden et al., 2009, page 1).
The article does not have a well-defined research question posed in an answerable form. Instead it has clear objective which is to evaluate the cost effectiveness of routine screening for postnatal depression in primary care (Paulden et al., 2009).
The economic research design used is Quality Adjusted Life Years (QALYs) which is appropriate to the stated objective. A QALY is a unit of measure of utility which combine life years gained as a result of health interventions /health care programmes with a judgement about the quality of life years (Jackson, 2012 pg. 114). However, QALYs examines only a single benefit when in reality public health interventions have many benefits (Kelly et al, 2005).
The main outcome is health outcome(s) associated with the mother and were expressed in terms of QALYs. The analysis was conducted from the National Health Services (NHS) and social services perspectives. The writer believes that Paulden at al., 2009 should have taken a wider perspective. In the article, no account was taken on the impact that successful identification and management of post natal depression might have on other family members or the child (ren). However, they justified this by stating that “a wider societal perspective, were not considered because of the lack of reliable evidence on the wider impact of case identification or treatment strategies” (Paulden et al., 2009 pg. 13).
The article was published in 2009. The year of costs was expressed in 2006-7 prices. Paulden et al., 2009 stated that they did not apply discounting because the time horizon was one year. Discounting is a technique which allows the calculation of present values of inputs and benefits which accumulate in the future (Jackson, 2012). The writer believes that they should have modelled costs for the future. The strength of this approach (discounting) is stated by the discount rate which is inserted in economic evaluations (Jackson, 2012). There was a major recession during the year(s) costs were expressed and the time the article was published. There is often a major time lag between the investment of health service resources and the arrival of the associated health gain. Therefore, people may prefer to receive benefits now and pay costs in the future (Haycoz, 2009).
All important and relevant costs for each alternative have been clearly identified in the paper. These include costs of administering the method, cost of any subsequent treatment and the costs associated with incorrect diagnosis (Paulden et al 2009). However these costs were identified from reviews (published data) or from experts. This may not reflect the true cost. For example, childcare or travelling costs to the family were not identified. The costs were measured in pounds and dollars. This could create a problem when converting the dollars to pounds because we do not know the conversion rate.
The impacts of the drivers on the results of the model used were explored through sensitivity analysis with a series of scenarios (Paulden et al., 2009). The incremental cost ratio of strategies adopting identification methods was more favourable than the ranking of non-dominated strategies. Costs of managing wrongly diagnosed depressed woman was assumed to be £25.50.
However, using the Edinburgh post natal depression scale seemed cost effective with an Incremental Cost Ratio (ICER) of £29186 per additional QALY (Paulden et al 2009 page 11, scenario 1). The ICER is usually calculated by finding the difference in costs between the two interventions divided by the difference in benefits (Jackson, 2012). This ratio helps to determine the extra cost per QALY or case detected (Drummond et al, 2005).
According to Jackson, 2012, Sensitivity analysis is a technique which repeats the comparison between inputs and consequences, varying the assumptions underlying the estimates. It tests the robustness of the conclusions by varying the items around which there is no uncertainty (Jackson, 2012 pg. 115). In the article, the study was modelled and was based on assumptions not true values. Therefore under base of their case assumptions (please see table 4), clinical interviews as a confirmatory test proved to be cost saving with the equivalent strategy without the interview. However, no strategy proved to be cost effective based on NICE threshold of £20 -30000 per QALY. The routine application of either post natal depression questionnaires or general depression questionnaires was not cost effective compared with routine care only.
The study discuses that their analysis was conducted from the National Health Service (NHS) and personal social services perspectives. They also clearly state that their model was focused on the costs and health outcomes associated with the mother only, no account was taken on other family members or the infant (Paulden 2009). Therefore, according to Evers at al., 2005 checklist the article discusses the generalizability of the results to other settings and client groups. It follows from the data reported-screening for postnatal depression in not cost effective. Methods for postnatal depression do not currently satisfy the National Screening Committee criteria for adopting a screening strategy as part of the national health policy (NICE 2007, Public Health, 2016).
Lastly, Paulden et al 2009’s article was/is a review or secondary research hence no ethical approval was required. There were no competing interests declared. They stated that their study was funded by NIHR Health Technology Assessment programme (HTA) and had no role in the study design or in the decision to submit the article for publication (Paulden et al., 2009). HTA publishes research information on the effectiveness, costs and broader impact of health technologies for those who use, manage and provide care in the NHS (NIHR Journals, 2016).
Explain why it is difficult to evaluate the effectiveness and cost effectiveness of complex public health interventions in the community.
Complex interventions are usually described as interventions that contain several interacting components (MRC, 2008). Health Economists interests are in how to make the best use of the limited or scarce resources available (Mcpake and Normand, 2008). They are concerned with how to allocate the limited or scarce resources and this is usually done through economic evaluation (Mcpake and Normand, 2008). Economic evaluation is defined as ‘the comparative analysis of alternative courses of action in terms of both their costs and consequences (Drummond et al., 2005 pg. 9). All economic evaluations have a common structure which involves explicit measurement of inputs (costs) and outcomes (benefits).
The first challenge of economic evaluation is the point of view from which the study should be conducted: from that of the health service, in which case only direct costs are considered; or from a societal viewpoint, in which case indirect costs are incurred (Haycoz, 2009). Paulden et al., 2009 article’s perspective was of the NHS and Social Services. They should have taken a wider perspective like the societal perspective.
The societal perspective reduces the likelihood that important costs will be excluded from the analysis simply because they fall outside the focus of the study (Haycoz, 2009). Using a societal perspective includes the costs and benefits openly encountered by the patient – postnatal depressed mother. Her costs, for, example, travelling costs to the clinic or even child care costs may be unnoticed from the NHS and social services perspectives yet they denote an important aspect of the economic analysis and evaluation. Therefore, economic evaluations and analyses must take the widest perspective to maximise their value as a basis for decision making. (Haycox, 2009).
The second challenge is that the main methods of economic evaluation vary in terms of their evaluation of health outcomes (Haycoz, 2009). The methods include; cost-benefit analysis, cost-consequence analysis, CEA, cost-minimisation analysis and cost-utility analysis (Kelly et al, 2005). These methods have different principles of economic evaluation. For example, the cost benefit analysis is the oldest approach to social impact. It uses experimental and quasi -experimental statistical methods for assessing causality (Kelly et al, 2005, Morris et al, 2012).
The method used by Paulden, et al., 2009 to examine screening for postnatal depression in primary care is CEA. CEA is the most widely used method of economic evaluation in which costs and benefits are measured. In CEA, a single outcome that is common to the two groups or alternatives is measured in natural units such as morbidity prevented, mortality reduced and life-years gained. The ICER is usually calculated by finding the difference in costs between the two interventions divided by the difference in benefits. It helps to determine the extra cost per QALY or case detected (Drummond et al, 2005).
Most economic evaluation use QALYs. The use of QALYs is open to criticism by some scholars (Haycox, 2009). However, QALYs are used more in medical decision making including their use in informing very serious healthcare resourcing decisions. The decisions are always hard and challenging but the use of QALYs provides a methodological framework to work from (Jackson, 2012). It also allows decision makers to have more information, which may lead them to look more broadly at the benefits of a treatment than just surviving (Jackson, 2012).
Criticisms have bordered the weight attached to emotional and mental health problems, and the lack of consideration of the impact of health problems on the quality of life of carers and other family members, while much debate surrounds who should be involved in placing values on health states (Phillips, 2009). A NICE guideline on how it pays per QALY is between £20000 and £30000. However, some treatments such as end of life or ultra-orphan conditions have been advocated for higher thresholds (Phillips, 2009). QALYs also suffer from a lack of sensitivity when comparing the efficacy of two competing but similar drugs and in the treatment of less severe health problems.
Public health aims to protect and improve the nation\’s health and wellbeing, and reduce health inequalities (Public Health, 2016). One of the ways to protect and improve someone’s health is by offering prevention methods such as immunisation and screening. Screening helps identify those in the early stages of disease. Public health’s role is to make sure the population is offered population screening programmes. However, currently, their population screening list does not include screening for post- natal depression (Public Health, 2016). Screening for post-natal depression does not satisfy the National Screening Committee’s criteria for the adoption of a screening strategy as part of the national population health policy (Paulden, 2009).
However, other scholars argue that the approach of screening is likely to face challenges due to the decrease of traditional authority vested in medicine and science, the changing perceptions of the need to control risk and the increased use of genetic tests and tensions about health care funding (Raffle and Gray 2009, pg30).
Recent clinical guidelines issued by the National Institute for Health and Clinical Excellence (NICE) recommend the use of brief case finding questions to identify possible postnatal depression with the use of self-report measures such as the EPDS as part of their assessment (NICE, 2007). If a different tool for assessment is used such as the anxiety and depression scale (HADS) and used with a different service user group, for example, man. The guidance did not officially consider the cost effectiveness of the strategy (NICE, 2007). Despite the insecurity of using such tools for screening, the HTA proritised a review of the clinical and cost effectiveness of formal identification methods for post-natal depression in primary care (Hewitt et al, 2009).
The policy makers or the decision makers in the public health sector are usual of weighing and synthesizing new evidences in relatively constant methods. The methods could be influenced by the interpretations of structural interventions (MRC, 2008). They work through several indirect ways which may be very complex. Complex interventions have several interacting components that act independently and inter-dependently (MRC, 2008). Downstream interventions focuses on a narrow aspect of the health behavior while upstream focuses on the broader determinants of health (Denaux and Sassi, 2011). This may pose a challenge in evaluating the effectiveness and cost effectiveness of complex public health interventions in the community.
Finally, Theoretical Approaches provide a foundation to work from. In health economics, they enable economists to assess cost effectiveness. The approaches differ and could make it difficult to evaluate the effectiveness and cost effectiveness of public health interventions. When a decision is made on behalf of a community to provide certain services collectively, the aim may be to maximize the welfare of the whole community (Mcpake.et al., 2002). However, what works for an individual may not work for the whole community. Therefore, it is important that some theoretical approaches must be applied to the issue of how decisions are made on the use of resources (Mcpake et al., 2002).
Extra Welfarism –It has been argued that extra welfarism provides a more appropriate normative basis for economic evaluation than the welfare theory. It is based on Sen’s concept of capabilities-the ability to perform tasks rather than utility (Jan et al., 2005). Welfarism focuses on the objective of maximisation of utility (or welfare). Extra welfarism is about incorporating objectives either in addition to- instead of utility (Jan et al., 2005 pg. 15). Extra welfarism is usually based on the suggestion that health utility is more appropriate maximand on health care. The relationship between extra welfarism and Capabilities is based on the principle that health is instrumental to an individual in achieving life goals.
However, the Capability Approach provides a broader evaluative measure than the above (Coast et al., 2008). It does not prescribe any specific capabilities that should be evaluated hence why it is viewed as a broad framework for policy evaluation (Robeyeyns, 2006 cited in Coast et al., 2008). The capability approach suggests that the evaluation of programmes or interventions should be based on whether the individual is capable to function regardless he or she chooses to or not (Sen, 1993, cited in Coast et al., 2008)
In conclusion, Part A of the assignment has critically appraised Paulden’s et al 2009 article using the Evers et al 2005 critical appraisal checklist for economic evaluation. A number of challenges in carrying out economic evaluation in public health have been discussed in Part B. The issues of screening, different methodological and theoretical approaches all have an impact when evaluating the effectiveness and cost effectiveness of public health interventions.