Evidence map›Paper›PMID 28399510›Full record

ArticleBMJ open2017

Assessing dose-response effects of national essential medicine policy in China: comparison of two methods for handling data with a stepped wedge-like design and hierarchical structure.

Yan Ren, Min Yang, Qian Li, Jay Pan, Fei Chen, Xiaosong Li, Qun Meng

Abstract readComparative Study
In one paragraph

Article in BMJ open, 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 5 papers.

0numbers the graph read from it
0cells of the map it votes in
5citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

5 citing papers in PubMed.

  1. Article
  2. Article
  3. Article
  4. Gender differences in caregiving among a schizophrenia population.Psychology research and behavior management · 2019
    Article
  5. The Effect of China's National Essential Medicine Policy on Health Expenses: Evidence From a National Study.Inquiry : a journal of medical care organization, provision and financing
    Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors.

Yan RenWest China School of Public Health, Sichuan University, Chengdu, Sichuan, People's Republic of China.
Min YangWest China School of Public Health, Sichuan University, Chengdu, Sichuan, People's Republic of China.
Qian LiWest China Research Center for Rural Health Development, Sichuan University, Chengdu, Sichuan, People's Republic of China.
Jay PanWest China School of Public Health, Sichuan University, Chengdu, Sichuan, People's Republic of China.
Fei ChenWest China School of Public Health, Sichuan University, Chengdu, Sichuan, People's Republic of China.
Xiaosong LiWest China School of Public Health, Sichuan University, Chengdu, Sichuan, People's Republic of China.
Qun MengCenter for Health Statistical Information, National Health and Family Planning Commission of the People's Republic of China, Beijing, People's Republic of China.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

objectivesTo introduce multilevel repeated measures (RM) models and compare them with multilevel difference-in-differences (DID) models in assessing the linear relationship between the length of the policy intervention period and healthcare outcomes (dose-response effect) for data from a stepped-wedge design with a hierarchical structure.

designThe implementation of national essential medicine policy (NEMP) in China was a stepped-wedge-like design of five time points with a hierarchical structure. Using one key healthcare outcome from the national NEMP surveillance data as an example, we illustrate how a series of multilevel DID models and one multilevel RM model can be fitted to answer some research questions on policy effects.

settingRoutinely and annually collected national data on China from 2008 to 2012.

participants34 506 primary healthcare facilities in 2675 counties of 31 provinces. OUTCOME MEASURES: Agreement and differences in estimates of dose-response effect and variation in such effect between the two methods on the logarithm-transformed total number of outpatient visits per facility per year (LG-OPV).

resultsThe estimated dose-response effect was approximately 0.015 according to four multilevel DID models and precisely 0.012 from one multilevel RM model. Both types of model estimated an increase in LG-OPV by 2.55 times from 2009 to 2012, but 2-4.3 times larger SEs of those estimates were found by the multilevel DID models. Similar estimates of mean effects of covariates and random effects of the average LG-OPV among all levels in the example dataset were obtained by both types of model. Significant variances in the dose-response among provinces, counties and facilities were estimated, and the 'lowest' or 'highest' units by their dose-response effects were pinpointed only by the multilevel RM model.

conclusionsFor examining dose-response effect based on data from multiple time points with hierarchical structure and the stepped wedge-like designs, multilevel RM models are more efficient, convenient and informative than the multilevel DID models.

Indexed as

Drugs, EssentialHealth PolicyOutcome Assessment, Health CareResearch DesignChinaData CollectionHumansModels, StatisticalMultilevel AnalysisOutpatientsDrugs, EssentialChinaDose-response effectMultilevel Difference-in-Differences modelMultilevel repeated measures modelNational essential medicine policy

Identifiers

PMID28399510
PMCPMC5337672

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.