Traumatic Splenic Injury and Management
"Quality of Life and Clinical Outcomes of Treatment for Splenic Injury after Trauma"
Prospective study

(II) PROSPECTIVE

PRIMARY

Quality of life is assessed with the generic 26-item World Health Organization

Quality of Life-Bref (WHOQOL-Bref) [14] at 1 week, 1 month, 3 months, 6 months

and 1 year follow-up. This measure assesses four domains (Physical health,

Psychological health, Social relationships, and Environment) and a general

facet *Overall QOL and general health*.

The short-form (12) health survey is a shorter version of the SF-36, which is

used to evaluate individual patients health status, researching the

cost-effectiveness of a treatment and monitoring and comparing disease burden.



iMCQ (iMTA Medical Consumption Questionnaire): The iMTA Medical Consumption

Questionnaire (iMCQ), is a generic non disease specific instrument for

measuring (direct) medical costs. The instrument is a standardized

self-reported questionnaire.

The iMCQ includes questions related to frequently occurring contacts with

health care providers and can be complemented with extra questions that are

relevant for specific study populations. A manual is available for a structured

use of the questionnaire. Cost-prices be applied to the obtained healthcare

utilization by the iMCQ by using the Dutch manual for cost-analyses that is

written by iMTA on behalves of Zorginstituut Nederland (former CVZ). The iMCQ

can be combined with the iMTA Productivity Cost Questionnaire (iPCQ). With the

iPCQ indirect costs can be measured in addition to the direct costs as measured

by the iMCQ.



iPCQ (iMTA Productivity Cost Questionnaire): The impact of disease on the

ability of a person to perform work should be part of an economic evaluation

when a societal perspective is applied. A manual is developed containing

information on the modular

structure of the iPCQ and its scoring- and valuation methods that are used for

the cost calculations. The iPCQ is a generic non-disease specific questionnaire

and is applicable to national and international studies. Currently a Dutch

version version of the iPCQ are available. Both indirect cost due to

absenteeism as the productivity losses due to presenteeism (i.e. sick, but

working) are taken into account. Different methods exist to value productivity.

The human-capital method takes the patient*s perspective and counts any hour

not worked as an hour lost. By contrast, the friction-cost method takes the

employer*s perspective, and only counts as lost those hours not worked until

another employee takes over the patient*s work. By applying wage costs the

results of the iPCQ can be monetized and as such used in health economic

evaluations.

(II) PROSPECTIVE

SECONDARY

Furthermore the three treatments will be compared in terms of clinical

outcomes, recovery related outcomes and cost outcomes. Also imaging outcomes

will be investigated in the SAE group, thereby identifying morphological

(versus immunological) aspects of the spleen after endovascular treatment.



The following endpoints apply to each of the outcomes:

- Clinical: complications during and/or after treatment; failure rate

(technical, clinical); any re-intervention or additional therapy

- Recovery related: hospital stay (days); return to daily activities

- Cost: cost-utility analysis between SAE and splenectomy

- Imaging: how does the spleen morphologically look like, in patients who

underwent embolization treatment of the splenic artery in case of traumatic

splenic injury? Splenic morpholical characteristics such as: volume; necrosis;

splenosis; calcifications; chronic infarction morphology



The cost effectiveness of SAE compared to splenectomy will be assessed using a

Markov modeling approach taking into account uncertainty and using all

available data. The effectiveness will be expressed in the most common outcome

measure the Quality Adjusted Life year (QALY). The costs will be estimated from

a societal perspective.

For the cost-effectiveness study, data on quality of life, survival and costs

are needed.

- Quality of life will be calculated by the SF-12

- Survival will be derived from international clinical literature

- Costs will be divided in direct medical costs and the costs due to

productivity losses from a societal perspective. Costs are derived by

multiplying the (health care) utilization or productivity loss by the reference

price.

- Costs will be estimated according to the Dutch Manual for Costing in Economic

Evaluations, update 2010 (Hakkaart-van Roijen, Tan& Bouwmans 2010).

- Health care utilization and production losses will be derived from various

sources:

o questionnaires concerning patientÕs health care usage to be completed by

patients: iMTA Medical Consumption Questionnaire (iMCQ), iMTA productivity

costs questionnaire (iMPQ)

o hospital administrations for inpatient health care use will retrospectively

be assessed

- International literature

- Expert opinion

A bottom-up methodology will be used to compute costs; total number of medical

contacts will be multiplied with unit costs. Direct medical costs comprise all

costs directly relating to the prevention, diagnostics, therapy, rehabilitation

and care of the intervention.

Direct medical costs include costs associated to hospital admissions,

ambulatory hospital visits, medication, ambulatory care, medical aids etc.

Direct costs outside the healthcare sector are directly related to the

intervention, but generally do not incur within the formal healthcare system,

such as travelling costs and time costs of patients and their informal

caregivers. The shadow price method will be used to express informal care use

in terms of costs. Indirect costs outside the healthcare sector are costs

incurred outside the scope of the formal healthcare system arising as a

secondary effect of the intervention, such as productivity costs due to absence

or reduced efficiency during paid or unpaid work. The friction cost method will

be used for the calculation of costs due to production losses.



* Effects will be measured in QALYs, which constitute a combination of quality

of life and length of life. Quality of life will be measured in utilities.

Utilities express quality of life on a scale from 0 (death) to 1 (perfect

health). Utilities can be derived from the SF-12 (see previous section).

To conduct the cost effectiveness analysis a cost-effectiveness model will be

developed. This model will comprise two treatment arms, respectively SAE

compared to splenectomy . The cost-effectiveness study will be conducted

according to the most recent Dutch guidelines for pharmacoeconomic research

(Zorg Instituut Nederland, Diemen). As such, the study will be performed from

the societal perspective, which means that all costs and benefits should be

considered, regardless of by whom the costs are borne or to whom the benefits

accrue. The base case time horizon in the study will be 15 years. Alternative

time horizons may be used in scenario analyses.

Analytical modeling provides an alternative framework for economic evaluation

and allows using different data sources. In case of small number of patients a

modeling approach is the most appropriate method to assess cost-effectiveness.

The health economic model will be based on a disease specific model that will

be developed in close cooperation with the clinicians. A decision analytic

framework will be used in the shape of a probabilistic Markov model comparing

both interventions: SAE treatment with splenectomy. Disease progression will be

described using transitions between *states*, where a subject can move between

states or remain in the current state. A big advantage of using such a model is

the flexibility of a model to adapt to new insights from clinic practice or

information extracted from literature, datasets or expert opinion during the

study. The model will be constructed with Microsoft Excel 2010.