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Table 3 Quality indicators for cost of illness studies

From: The economic burden of diabetes in India: a review of the literature

General

 

Objective of the study

Cost of drugs: studies that aim to calculate the cost of a specific drug

General Costs: studies that aim to calculate direct or indirect costs for the diabetes in general, for ambulatory care or for a specific subgroup.

Cost of Complication: studies that aim to calculate the cost of a specific complication of diabetes.

How is the disease defined?

Diabetes type 1/Diabetes type 2/ Gestational diabetes

Is the definition clear and precise?

1 = the definition of the type of diabetes considered is clear and all the morbidities and co-morbidities considered are listed. 0 = the definition is vague and do not include any details of all the morbidities and co-morbidities considered

Which complications the authors have included?

1 = more than 4 complications are considered and specified.

0,5 = up to 3 complications are considered for each patient but they are not specified.

0 = no complications are considered or if they are considered there is no clear documentation in their inclusion.

Is a clear epidemiological definition provided?

The type of diabetes studied is specified

SAMPLE

 

Which is the population sample considered?

Description of the population considered by the study.

Is the population selected appropriate?

The sample size is sufficiently large and the epidemiological characteristics of the population are in line with the objectives of the study. For example, a large national assessment of diabetes requires a large sample with a balanced population composition in terms of social class, the gender and other factors such as the education level. For a study focused on the costs of drug an appropriate sample could be small but should be focused on a particular health history of patients.

Are sources for population data reliable?

1 = self-assessment and questionnaire are confirmed by hospital records or hospitals and practitioners’ bills.

0,5 = The only sources of data are questionnaire and self-assessment.

0 = The sources of data are not defined or are subject to a number of biases.

The period of evaluation is appropriate?

A period of evaluation is considered appropriate if is equal or more than 6 months for prevalence- based studies and consider more than 1 year for incidence based studies.

COSTS

 

Direct costs:

All resource costs employed to treat patients with diabetes (care and/or assistance). It includes medical and non-medical costs.

Indirect costs:

All the costs associated with the loss of productivity resulting from morbidity and mortality caused by diabetes.

Intangible costs:

All the costs associated with all the negative effects caused by the disease leading to deterioration in the quality of life of patients (e.g. isolation, anxiety, pain).

Healthcare costs

 

People with the health condition

Premiums and levies paid to collectively financed healthcare systems; out-of-pocket costs of healthcare services and products; transport costs related to treatment; home and car modifications; special diets; domestic care; lost income for unpaid leave to attend treatment.

Others, including family members

Premiums and levies paid to collectively financed healthcare systems; out-of-pocket costs of healthcare and domestic services and products and home and car modifications for sick family members.

Healthcare system (public and private)

Hospitals; primary care services; nursing homes; pharmaceuticals; domiciliary care; rehabilitation; home nursing; medical specialists; general practitioners; community healthcare services; ambulance services; paramedical services; specialist equipment; diagnostic tests; training; research; infrastructure; equipment; preventive programmes; administration

Business/industry/employers (includes government employers)

Premiums and levies paid to collectively financed healthcare systems; preventive programmes

Government (excluding health care system)

Specialist equipment/infrastructure modifications; community support services; residential support services; preventive programmes (e.g. education and training)

Other resource use

 

People with the health condition

Legal representation; childcare

Others, including family members

Damage to property (e.g. for substance abuse, smoking), crime-related costs (e.g. for substance abuse)

Healthcare system (public and private)

None

Business/industry/employers (includes government employers)

Worker replacement costs (recruitment, training, retraining); cost of implementing and adhering to regulation and legislation

Government (excluding health care system)

Regulation, inspection and monitoring; child welfare services; disability support services; courts services; police services; prison services; emergency/fire services; cost of administering additional taxes, levies and benefits.

Production losses

 

People with the health condition

Lost income due to unpaid sick leave (absenteeism), treatment related time off work, temporary unemployment, reduced on-the job productivity (‘presenteeism’), premature retirement through morbidity or early mortality, unwanted job changes, loss of opportunities for promotion and education; loss of unpaid production while ill.

Others, including family members

Loss of income and unpaid production while caring for sick family members and friends.

Healthcare system (public and private)

None

Business/industry/employers (includes government employers)

Lost paid and unpaid output due to sickness (absenteeism for paid output), treatment-related time off work, temporary unemployment, reduced capacity, reduced on-the job productivity (‘presenteeism’), work injury, premature retirement through morbidity or early death

Government (excluding health care system)

None

Intangible costs

 

People with the health condition

Quality of life (health, functioning, psychosocial impacts, including loss of leisure time), premature loss of life

Others, including family members

Psychosocial costs related to family members’ suffering; Quality of life lost providing care to family members

Healthcare system (public and private)

None

Business/industry/employers (includes government employers)

Employee morale

Government (excluding health care system)

Deadweight loss of additional taxation

Appropriateness

 

Does the study include the relevant costs?

1 = the costs included are relevant for the objective of the stud. (minimum of 80% of the costs included in the section costs of this table)

0,5 = the inclusion of the costs is partial

0 = there are missing a large number of costs that should be included or there is no specification of the costs included

Are the inclusion of the costs appropriate for the objective of the study?

1 = considering the aim, all the necessary type of costs are included. (for ex for the evaluation of direct costs of a drug treatment all the costs borne by the patients directly and by the health care are included)

0,5 = Only partial relevant costs are included. There are missing of some important costs related to the aim of the study.

0 = Although the study aim is to consider a general costs of diabetes or a costs of drug or complications there are included only a category of costs (for ex direct costs).

Has the Diabetes severity Index been used?

1 = Yes

0 = No

Is adequate documentation and justification given for cost components, data and sources, assumptions and methods?

1 = detailed justifications are given for all the approach and methods adopted. The exclusion and inclusion of categories of cost and data are well motivated. All the sources are documented.

0,5 = partial justification is given for the methods and approach adopted. There is limited or absence of justifications for the inclusion or exclusion of costs. The documentation is scarce and not precise.

0 = absence or minimal presence of documentation and justification

Are important limitations discussed regarding the cost components, data, assumptions and methods?

1 = all the most important limitations are discussed. In same cases some minor limitation is discussed.

0,5 = one or only not important limitations are discussed.

0 = there is no discussion around the limitations of the study.

METHODS

 

Which is the epidemiological approach employed?

A) Prevalence-based: estimates the total cost of a disease in a given population for a given period. (Static)

B) Incidence-based: estimates the potential averted costs if new (incident) cases are prevented. (Dynamic)

Is the data representative of the study population?

1 = prevalence-based

0, 5 = Incidence based

0 = no definition of the approach considered

Which approach in quantification of the costs were used?

A) Top-down approach refers to aggregate data available at national level, and involves a process of relating the overall health care spending to the individual diseases. From a methodological point of view to estimate the costs with the top-down method is crucial an excellent databases.

B) The bottom-up approach refers to the direct consumption of resources, including epidemiological data, the cost of individual factors and the costs by the product, the average consumption of resources and its price/cost.

Was the approach appropriate?

1 = bottom-up approach.

0,5 = top down.

0 = no approach defined/ or impossibility to infer the approach employed

Which is the method used to evaluate the value of health?

A) Human Capital approach (generally recommended)

B) Friction Costs approach.

C) Willingness to pay.

How is used the discount?

Discounting is an economic method that captures an individual’s preference for income today rather than income in the future. This time preference is often explained by the opportunity-cost of interest. Income earned today can earn interest through investment.

Is the approach appropriate?

Discounting is relevant for direct and indirect costs and health outcomes that accrue past the first year.

How are estimated the costs and health outcomes ?

A) Total disease costs: estimating of the total health-care expenditure of people diagnosed with diabetes.

a) Sum_All Medical costs: Identify all patients with a diagnosis and sum costs

b)Sum_Diagnosis Specific: Identify all patients with a primary diagnosis and sum costs for treatments for that diagnosis

B) Incremental costs: estimating the increase in costs that is attributable solely to the presence of the diabetes:

a) Matched Control: Identify all patients with a diagnosis and sum cost. Subtract out the average cost of the sample to find incremental costs for treatment; alternatively, subtract out the average cost of a matched cohort instead

b) Regression_Method: Identify all patients with a diagnosis, complete a regression analysis and indicate the individual β for each diagnosis

Identify all patients with a diagnosis, find a matched cohort (similar to a clinical trial) and complete a regression analysis to quantify the individual β for each diagnosis – gold standard

Is the estimation method of the cost of diabetes appropriate?

1 = Incremental costs method.

0,5 = Total disease costs

0 = no methods designed or impossibility to retrieved a clear method from the study.

Are the deviation standard and the means calculated?

1 = both, standard deviation and Means are calculated. 0,5: only one of them is calculated. 0: none of them is calculated

Is a sensitivity analysis performed?

1 = the sensitivity analysis is performed and the results are clearly shown.

0,5 = some linear regression method are employed to correlate the variables

0 = no sensitivity analysis or linear regression are performed.

If yes, is it performed on:

1) Important (uncertain) parameter estimates

2) Key assumptions

3) Point estimates

Which statistical methods are used

1 = the statistical analysis is performed with consistent statistical formulas. The formulas used should non-parametrical statistical hypothesis test.

0,5 = the statistical analysis is performed but only with few statistical tools.

0 = no statistical methods are used.