Pay for Quality

KCE Reports 118 Pay for Quality 35
4 THE EVIDENCE BASE FOR P4Q: A
SYSTEMATIC REVIEW OF THE PEER
REVIEWED LITERATURE
4.1 INTRODUCTION
In this chapter the evidence from peer reviewed literature for P4Q is reported. This
chapter starts from a systematic review of the already published primary P4Q evaluation
studies.
The aim is to come to a comprehensive overview of results in terms of P4Q effects in
relationship with their context, design and implementation process. Due to the amount
of newly available research findings, there is a need for a synthesis that strengthens the
applicability of theoretical P4Q concepts.
The following research question is addressed:
What is the effect of P4Q on the different quality domains (effectiveness,
equity, safety, coordination, cost effectiveness, etc.), describing both
intended and unintended consequences?
The methods used for this review are described in Chapter 2. Chapter 4 focuses on the
empirical evidence, based on the experience with or observation of P4Q programmes.
Equity related aspects were described in a separate paragraph (see paragraph 0).
4.2 DESCRIPTION OF STUDIES
4.2.1 General description
Appendix 15 provides an overview of the 104 studies that were included in the review.
The number of P4Q evaluation studies increases steadily. In the nineties only a few
studies were published each year. Since 2000, this number is increasing rapidly to more
than 20 studies per annum in 2007 and 2008.
The majority of studies are from American or British origin. In the period 1990-2008,
54 studies were published in the USA and 45 in the UK. Two studies were conducted in
Australia while Italy, Germany and Spain each published one evaluation study on P4Q.
There are also a limited number of Canadian, Swedish, Czech, Estonian, Chinese and
Taiwanese P4Q publications. However, none of these described an empirical P4Q
evaluation and were therefore excluded from further analysis in this Chapter.
Of a total of 104 studies, 91 evaluate P4Q use in a primary care setting while 25 studies
focused on a hospital setting. Some of these studies take place in both settings.
In terms of study design, studies are classified in six groups:
• ‘Randomized’ : randomized controlled trials and cluster randomized
controlled trials with randomization of group allocation;
• ‘Concurrent + Historic’ : studies in which evaluation over time is combined
with a concurrent control group without randomization;
• ‘Concurrent’ : studies with a concurrent control group, without an evaluation
over time and without randomization;
• ‘Historic, Multi’ : studies with evaluation over time with more than two time
points of data collection, without a concurrent control group and without
randomization;
• ‘Historic, before-after’ : studies with evaluation over time with two time
points of data collection, without a concurrent control group and without
randomization;