The phrase "a previous study extended" is correct and usable in written English.
It can be used when referring to a study that has built upon or added to the findings of an earlier research work.
Example: "In this paper, we discuss how a previous study extended the understanding of climate change impacts on agriculture."
Alternatives: "an earlier study expanded" or "a prior study enhanced".
In this study, we generalised the previous studies, extended the concept of estuary wetland ecological integrity and developed a multi-scale evaluation index system including environmental quality, biology and ecology, landscape pattern and ecosystem management (EBLE) based on dissipation theory.
In a previous study, we extended this observation on 66 C. canimorsus strains but noticed that a few strains, isolated from dogs could ferment sucrose and raffinose.
In a previous study, an extending homologous recombination approach was demonstrated by assembling a megaplasmid from multiple overlapping fragments in a single step in S. cerevisiae[ 22].
We used genetic data from a previous study [19] to extend our analyses of the population structure of A. transcaspicus in the Mediterranean.
This study extends a previous study from Denmark during 1995 2005, 12 which showed that 5% of ovarian cancer had severe comorbidity at diagnosis and that comorbidity was associated with reduced survival of ovarian cancer patients.
We used the ratio of exposure to toxicity (REXTOX) model proposed by the OECD, which had been successfully validated in the study area as part of a previous study and which was extended to calculate pesticide concentrations in adjacent streams.
In a previous study the mean sensory extend of a bilateral TAP block with 2 × 20 mL of ropivacaine were 6 dermatomes (SD 1.7) for pinprick evaluated 30 minutes after block performance [ 5].
Estimates come from a previous study but this could be extended to multiple previous studies.
We thereby extended a previous study from our regions, covering ovarian cancer survival in the period 1985–2004.
To clarify this we have extended a previous study to type DPB1 alleles in 147 adult HD patients from a single centre.
