Sentence examples for primary studies are needed from inspiring English sources

Additional primary studies are needed to consolidate the results of our review.

As illustrated in the results, an evidence map of a specific topic can also avoid duplication of primary research and determine where further primary studies are needed or conversely, identify if a systematic review of existing studies may be more appropriate.

From this, we will identify where there is a need for a systematic review of the literature (eg, there may be sufficient literature on validated risk stratification techniques) and where gaps in the literature exist and primary prospective studies are needed.

More experimental (ie, effect evaluation studies of family-focused interventions targeting PA and screen time of primary schoolchildren) and longitudinal studies are needed to provide evidence for predictive associations between parenting-related factors and children's PA and screen time.

Recent interventions and changes in healthcare delivery may have resulted in changes in disease burden in the community and presenting to primary care; population-based studies are needed to monitor such changes.

These findings revealed that a considerable proportion of patients with extensive distant metastases could benefit from radiotherapy for primary NPC, and further studies are needed to identify the targeted patients.

Elevated Ca antigen levels were found in 50% of patients with metastatic spread (median 30.7 micrograms ml-1, range 8.2- greater than 100 micrograms ml-1) and in some patients with primary disease but further studies are needed to determine the prognostic significance.

The evidence is less persuasive for reduction in infections and dehiscence in uncomplicated primary joint replacement and further studies are needed.

Thus, if infections occur over time, our results may suggest a limited Genus-, serogroup- and species- specific protection of pigs after a primary Salmonella infection, but further studies are needed for a better understanding of the host-pathogen interactions.

Many other non-pharmacological treatments are useful in the prevention of primary headaches, although further well-conducted studies are needed to support their efficacy.

Rebound attacks were not observed after nVNS discontinuation in the current trial or in previous studies of primary headache conditions [16 19], but additional studies are needed to rule out the potential for post-nVNS migraines.