Information and user choice in primary health care markets

Last registered on November 04, 2024

Pre-Trial

Trial Information

General Information

Title
Information and user choice in primary health care markets
RCT ID
AEARCTR-0000659
Initial registration date
May 08, 2015

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
May 08, 2015, 4:55 AM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Last updated
November 04, 2024, 8:46 AM EST

Last updated is the most recent time when changes to the trial's registration were published.

Locations

Region

Primary Investigator

Affiliation
University of Gothenburg

Other Primary Investigator(s)

PI Affiliation
Lund University
PI Affiliation
Lund University
PI Affiliation
SFI - The Danish National Centre for Social Research

Additional Trial Information

Status
Completed
Start date
2015-02-04
End date
2017-08-31
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
In order to increase quality of care, all regions in Sweden have during the last decade implemented systems where users can choose their primary health care provider, and where there is freedom of establishment for providers. All primary health care units are financed by public means and pre-set user fees, but may be privately or publicly run. For user choice systems to improve the functioning of health care, users must choose health care units that deliver care of relatively high-quality. Previous studies indicate that a very large share of users in Sweden do not compare the quality of providers before making their choice of provider. The transaction costs related to information retrieval and switching present a possible obstacle to the functioning of this market: the gathering of information about and comparison of providers is costly in terms of time, and there are also (small) process costs related to notifying providers of the change. In this study, we provide three randomly drawn samples of the population in the region of Skåne with information about the quality of primary care providers, to see whether this freely available information affects their propensity to change provider, and the type of provider they choose. The first sample is representative of the whole population in the region (above 18 years of age), the second consists of individuals that have recently moved to the region, and the third sample consists of families that are expecting children. We also examine if lowering the process costs on top of providing free information affects the choice frequency, and whether the effects differ for groups defined by for example socioeconomic background and health status.
External Link(s)

Registration Citation

Citation
Anell, Anders et al. 2024. "Information and user choice in primary health care markets." AEA RCT Registry. November 04. https://doi.org/10.1257/rct.659-4.0
Former Citation
Anell, Anders et al. 2024. "Information and user choice in primary health care markets." AEA RCT Registry. November 04. https://www.socialscienceregistry.org/trials/659/history/240936
Sponsors & Partners

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Experimental Details

Interventions

Intervention(s)
There are three parts to the experiments:

Part 1: In this part, the regional health authority in the region of Skåne (located in the south-west of Sweden) - Region Skåne - provides 1 percent of the population that are over 18 years old with information about the primary care center that they are listed at and its three geographically nearest competitors. The information is sent by mail, and contains information about, among other things, opening hours, quality ratings, and special competences. Within the 1 percent group, there are two treatments: one group receives only information about primary care centers (T1), the other receives this information along with a pre-paid form that notifies the new and old provider about the change (T2).

Part 2: The procedure for this part is similar to the one described for Part 1, it is basically only the target group that differs. In Part 2, information will be sent specifically to individuals who have recently moved to Skåne. There may be such individuals also in the sample for Part 1, but they are a very small subset.
Intervention (Hidden)

Part 3: The sample in this experiment consists of families that are expecting children. All such families must choose a child welfare center/children’s clinic (“barnavårdscentral”) for their child before birth, or the child is by default listed at the center closest to where the family lives. The regional health authority in Skåne will provide a random sample of these families with information about their default primary care center and its three nearest competitors. The information is sent by mail, and contains information about, among other things, opening hours, quality ratings, and special competences.
Intervention Start Date
2015-02-24
Intervention End Date
2015-09-01

Primary Outcomes

Primary Outcomes (end points)
The outcome variables of main interest are the frequency of choice, and the type of primary care providers chosen by users in our samples.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The premise for Part 1 is that the regional health authority has to treat all primary care centers equally, in order to be neutral in terms of competition on this market. Using the random number generator within Stata (which we use for all randomizations), we therefore first draw 11 percent of listed individuals over 18 from each of the 150 primary care centers. Then, we randomly select 9.0909091 percent of these 11 percent, which constitute the treatment group. In total, this procedure implies that 1 percent of the total population over 18 will be treated. The remaining 10 percent constitutes the control group. Among the treatment group, we then randomly assign 25 percent to the group that only receives information (T1), and 75 percent to the group that receives information and a pre-paid change form (T2).

In Part 2, we randomly select 6906 individuals (6059 clusters based on residential address) into treatment and control. The treated group recieves the same information and a pre-paid change form.

Several details about how we will conduct the randomization for Part 3 are presently not known. For administrative reasons Part 3 is postponed.
Experimental Design Details
Randomization Method
Part 1: Using the random number generator within Stata (which we use for all randomizations), we therefore first draw 11 percent of listed individuals over 18 from each of the 150 primary care centers. Then, we randomly select 9.0909091 percent of these 11 percent, which constitute the treatment group. In total, this procedure implies that 1 percent of the total population over 18 will be treated.

Update: Part 2: We randomly assigned clusters of individuals (based on the residential adress) to treatment and control groups using random number generator within Stata. These individuals had that entered the primary care enrolment register held by Region Skåne between Feb 4 and May 11.
Randomization Unit
The unit of randomization is for Part 1 individuals, Part 2 is address (i.e., household) and Part 3 antenatal care centers.
Was the treatment clustered?
Yes

Experiment Characteristics

Sample size: planned number of clusters
Part 2: Number of addresses/households in the sample is currently unknown. (Update: 6,059 clusters) Part 3: 80 antenatal care centers.
Sample size: planned number of observations
Part 1: Total sample is 112 861 individuals. Part 2: Total sample 6,906. Part 3: yet to be implemented.
Sample size (or number of clusters) by treatment arms
Part 1: T1 = 2,559, T2 = 7,700, and the control group = 102,602. Part 2: T: 3,454 Control: 3,452 and Part 3: yet to be implemented.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB

Institutional Review Boards (IRBs)

IRB Name
Regionala Etikprövningsnämnden Lund
IRB Approval Date
2014-06-11
IRB Approval Number
Dnr 2014/49
Analysis Plan

Analysis Plan Documents

Analysis_plan

MD5: 54a615bf41fa52a109c55652f0697164

SHA1: 4c6aeda273807f532fdee0758395dae7ecf097b1

Uploaded At: May 08, 2015

Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
No
Data Collection Complete
Yes
Data Collection Completion Date
Final Sample Size: Number of Clusters (Unit of Randomization)
Part 1: 112,859 individuals.
Part 2: 6,059 clusters (6,906 individuals clustered by residential address)
Was attrition correlated with treatment status?
No
Final Sample Size: Total Number of Observations
Part 1: 112,859 individuals. (137 individuals died or left the region before we extracted address information (for administrative reasons, address data was extracted after the randomization date. One individual chose to opt out from the study after randomization. In accordance with the recommendation from the regional ethical board, we gave all individuals the option to not be a part of the study, by announcing the project in two local newspapers in August 2015 (i.e., after the interventions). This is a standard procedure when using register data in Sweden. Note that the advertisements did not mention neither the information campaign nor the experimental set up.

Part 2: 6,906 individuals. Among these we have complete information from the health authority's registers for all but one individual.
Final Sample Size (or Number of Clusters) by Treatment Arms
In Part 1: 6,906 individuals (6,059 clusters)
Data Publication

Data Publication

Is public data available?
No

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Abstract
Consumer choice policies may improve the matching of consumers and providers, and may spur competition over quality dimensions relevant to consumers. However, the gains from choice may fail to materialise in markets characterised by information frictions and switching costs. We use two large-scale randomised field experiments in primary health care to examine if individuals reconsider their provider choice when receiving leaflets with comparative information and pre-paid choice forms by postal mail. The first experiment targeted a representative subset of the 1.3 million residents in a Swedish region. The second targeted new residents in the same region, a group expected to have less prior information and lower switching costs than the general population. The propensity to switch providers increased after the interventions in both the population-representative sample (by 0.6–0.8 percentage points, 10–14%) and among new residents (2.3 percentage points, 26%). The results demonstrate that there are demand side frictions in the primary care market. Exploratory analyses indicate that the effects on switching were larger in urban markets and that the interventions had heterogeneous effects on the type of providers chosen, and on health care and drug consumption.
Citation
Anell, A., Dietrichson, J., Ellegård, L. M. & Kjellsson, G. (2021). Information, switching costs, and consumer choice: Evidence from two randomized field experiments in Swedish primary health care. Journal of Public Economics, 196, 104390

Reports & Other Materials