Oshitani 2000.
| Methods | Purpose: to assess the effect of staff and resident influenza vaccination rates on resident influenza‐like illness (ILI) Design: prospective cohort study assessing the effectiveness of influenza vaccination levels in patients of long‐term nursing care facilities (LTCIs) by vaccination coverage rates of HCWs (less than 10 or more than 10 vaccinated HCWs per facility), in Niigata, Japan. Niigata Prefecture and Niigata City conducted mandatory surveys of influenza vaccine status and occurrence of ILI every 2 weeks from January to March 1999. During this period more than 20% of facilities had outbreaks and more than 10% of residents experienced ILI during an influenza A (H3N2) epidemic. All LTCIs in Niigata Prefecture provided reports. Information (assumed questionnaires) included number of residents in each institution, number of vaccinated residents and staff and weekly ILI in residents. No ILI definition is reported An influenza outbreak was defined as 10% of more of the residents in a home reporting ILI symptoms during a week 2 types of LTCIs, special nursing homes for the elderly and geriatric health services facilities, were used. Both are for the elderly who need constant care, special nursing homes are for the elderly who have more severe conditions Statistics: X2 and Fisher's exact test for univariate analysis. X2 for linear trend and Mantel‐Haenszel ORs for different categories of resident vaccination rates. Logistic regression for multivariate analysis of outbreak status | |
| Participants | Country: Japan Setting: 149 LTCIs in Niigata Prefecture and Niigata City Eligible participants: the text reports 12,784 residents in 149 facilities were included in the study with 3933 (30.8%) vaccinated and 7459 staff with 1532 (20.5%) vaccinated. However, table 2 shows 8669 residents living in homes where fewer than 10 staff were vaccinated and 4073 living in homes with 10 staff vaccinated, for a total of 12,742. The totals for residents living in homes with fewer than 10 staff vaccinated is given as 8699 but the subcategories add to 8669 and for the homes where 10 staff were vaccinated the total is given as 4085 but the subcategories add to 4073 Age: not stated Gender: not stated | |
| Interventions | Intervention: trivalent influenza vaccine containing A/Beijing/262/95 (H1N1), A/Sydney/5/97 (H3N2) and B/Mie/1/93, which was a good match against the circulating strain. No mention of pneumococcal vaccination is made Control: no control group | |
| Outcomes | ILI (no case definition). During the period of surveying the number of ILI cases per week exceeded 10% of the residents in 34 (22.8%) of facilities | |
| Notes | Choice of outcome is inappropriate (ILI is a non‐specific outcome) Assessment of the Oshitani study was undertaken with the Newcastle‐Ottawa scale (see Appendix 7) |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | ‐ |
| Allocation concealment (selection bias) | Unclear risk | ‐ |
| Blinding (performance bias and detection bias) All outcomes | Unclear risk | ‐ |
| Incomplete outcome data (attrition bias) All outcomes | Unclear risk | ‐ |
| Selective reporting (reporting bias) | Unclear risk | ‐ |
| Other bias | Unclear risk | ‐ |